Method and apparatus for requesting scheduling in wireless communication system

ABSTRACT

Disclosed herein are a method and apparatus for requesting scheduling in a wireless communication system. More specifically, a method of requesting scheduling for transmitting uplink data in a wireless communication system may include transmitting, by user equipment (UE), a Scheduling Request (SR) of an SR type selected from multiple SR types to an eNB, receiving, by the UE, an uplink grant determined according to the selected SR type from the eNB, and transmitting, by the UE, uplink data to the eNB through a physical uplink shared channel (PUSCH) resource allocated by the uplink grant.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is the National Stage filing under 35 U.S.C. 371 ofInternational Application No. PCT/KR2015/002280, filed on Mar. 10, 2015,which claims the benefit of U.S. Provisional Application No. 62/026,009,filed on Jul. 17, 2014, the contents of which are all herebyincorporated by reference herein in their entirety.

TECHNICAL FIELD

The present invention relates to a wireless communication system and,more particularly, to a method for requesting, by User Equipment (UE),scheduling from a Base Station (BS) in order to send uplink (UL) data tothe eNB and an apparatus for supporting the same.

BACKGROUND ART

Mobile communication systems have been developed to provide voiceservices, while guaranteeing user activity. Service coverage of mobilecommunication systems, however, has extended even to data services, aswell as voice services, and currently, an explosive increase in traffichas resulted in shortage of resource and user demand for a high speedservices, requiring advanced mobile communication systems.

The requirements of the next-generation mobile communication system mayinclude supporting huge data traffic, a remarkable increase in thetransfer rate of each user, the accommodation of a significantlyincreased number of connection devices, very low end-to-end latency, andhigh energy efficiency. To this end, various techniques, such as smallcell enhancement, dual connectivity, massive Multiple Input MultipleOutput (MIMO), in-band full duplex, non-orthogonal multiple access(NOMA), supporting super-wide band, and device networking, have beenresearched.

DISCLOSURE Technical Problem

In mobile communication systems, in order to maximize resourceutilization, a method of transmitting and receiving data through aresource allocation procedure based on base station scheduling. However,this causes to increase latency in uplink data transmission of a userequipment.

An object of the present invention is to propose the definition ofmultiple Scheduling Request (SR) types for minimizing the latency of UEin a wireless communication system.

Another object of the present invention is to propose a method forenabling UE to rapidly send UL data through a specific SR type if the ULdata to be transmitted by the UE is generated from an applicationsensitive to delay or if the UE intermittently sends small data.

The technical problems solved by the present invention are not limitedto the above technical problems and those skilled in the art mayunderstand other technical problems from the following description.

Technical Solution

In an aspect of the present invention, a method of requesting, by userequipment (UE), scheduling for transmitting uplink data in a wirelesscommunication system may include transmitting, by the UE, a SchedulingRequest (SR) of an SR type selected from multiple SR types to an eNB,receiving, by the UE, an uplink grant determined according to theselected SR type from the eNB, and transmitting, by the UE, uplink datato the eNB through a physical uplink shared channel (PUSCH) resourceallocated by the uplink grant.

In another aspect of the present invention, user equipment that requestsscheduling for transmitting uplink data in a wireless communicationsystem may include a Radio Frequency (RF) unit for sending and receivingradio signals and a processor. The processor may be configured totransmit a Scheduling Request (SR) of an SR type selected from multipleSR types to an eNB, receive an uplink grant determined according to theselected SR type from the eNB, and transmit uplink data to the eNBthrough a physical uplink shared channel (PUSCH) resource allocated bythe uplink grant.

At least one of an index of a physical uplink control channel (PUCCH)resource, an SR periodicity, or an SR subframe offset for sending the SRmay be differently configured according to each of the multiple SRtypes.

The size of the uplink data may be determined for each of the multipleSR types.

The PUSCH resource allocated by the uplink grant may be determined basedon the size of the uplink data according to the selected SR type.

The size of a soft buffer set by the eNB may be determined based on thesize of the uplink data according to the selected SR type.

A resource allocation procedure for sending the uplink data may bedetermined according to the multiple SR types.

The user equipment may receive multiple SR configuration information forconfiguring the multiple SR types from the eNB.

The multiple SR configuration information may include at least any oneof information about an index of a PUCCH resource, an SR periodicity, oran SR subframe offset corresponding to each of the multiple SR types.

If the SR is an SR for sending the BSR, the user equipment may receivean uplink grant for sending a Buffer Status Report (BSR) from the eNBand send the BSR to the eNB through the PUSCH resource allocated by theuplink grant for sending the BSR.

Advantageous Effects

In accordance with an embodiment of the present invention, delayattributable to the assignment of UL resources can be reduced by newlydefining multiple SR types.

Furthermore, in accordance with an embodiment of the present invention,UL data generated from an application sensitive to delay or intermittentUL data of a small size can be rapidly transmitted by newly defining ascheduling request signal.

The effects of the present invention are not limited to theabove-described effects and other effects which are not described hereinwill become apparent to those skilled in the art from the followingdescription.

DESCRIPTION OF DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this application, illustrate embodiment(s) of the invention andtogether with the description serve to explain the principle of theinvention.

FIG. 1 illustrates a schematic structure a network structure of anevolved universal mobile telecommunication system (E-UMTS) to which thepresent invention can be applied.

FIG. 2 illustrates the configurations of a control plane and a userplane of a radio interface protocol between the E-UTRAN and a UE in thewireless communication system to which the present invention can beapplied.

FIG. 3 illustrates physical channels and a view showing physicalchannels used for in the 3GPP LTE/LTE-A system to which the presentinvention can be applied.

FIG. 4 is a diagram showing the structure of a radio frame used in a3GPP LTE system to which the present invention can be applied.

FIG. 5 shows an example of a resource grid for one downlink slot in thewireless communication system to which the present invention can beapplied.

FIG. 6 shows a structure of a downlink subframe in the wirelesscommunication system to which the present invention can be applied.

FIG. 7 shows a structure of an uplink subframe in the wirelesscommunication system to which the present invention can be applied.

FIG. 8 illustrates a structure of DCI format 0 in the wirelesscommunication system to which the present invention can be applied.

FIG. 9 illustrates an example of a formation that PUCCH formats aremapped to the PUCCH regions of the UL physical resource blocks in thewireless communication system to which the present application can beapplied.

FIG. 10 shows a structure of CQI channel in case of a normal CP in thewireless communication system to which the present invention can beapplied.

FIG. 11 shows a structure of ACK/NACK in case of a normal CP in thewireless communication system to which the present invention can beapplied.

FIG. 12 illustrates a method for multiplexing the ACK/NACK and the SR inthe wireless communication system to which the present invention can beapplied.

FIG. 13 illustrates the MAC PDU used in the MAC entity in the wirelesscommunication system to which the present invention can be applied.

FIG. 14 and FIG. 15 illustrate the sub-header of the MAC PDU in thewireless communication system to which the present invention can beapplied.

FIG. 16 illustrates formats of the MAC control elements in order toreport the buffer state in the wireless communication system to whichthe present invention can be applied.

FIG. 17 represents an example of component carrier and carrieraggregation in the wireless communication system to which the presentinvention can be applied.

FIG. 18 illustrates a UL resource allocation procedure of a UE in thewireless communication system to which the present application can beapplied.

FIG. 19 is a diagram for describing a latency in C-plane required in3GPP LTE-A to which the present invention can be applied.

FIG. 20 is a diagram for describing a transition time from the dormantstate to the active state for a synchronized UE required in 3GPP LTE-Ato which the present invention can be applied.

FIG. 21 is a diagram for describing the soft buffer in the wirelesscommunication system to which the present invention can be applied.

FIG. 22 is a diagram illustrating SR resources according to SR types inaccordance with an embodiment of the present invention.

FIG. 23 is a diagram illustrating a method for requesting scheduling fortransmitting UL data in accordance with an embodiment of the presentinvention.

FIG. 24 is a diagram illustrating a process of sending UL data using amultiple SR configuration in accordance with an embodiment of thepresent invention.

FIG. 25 is a diagram illustrating a method for requesting scheduling fortransmitting UL data in accordance with an embodiment of the presentinvention.

FIG. 26 is a block diagram illustrating the configuration of a wirelesscommunication apparatus in accordance with an embodiment of the presentinvention.

MODE FOR INVENTION

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings. The detailed description set forth below in connection withthe appended drawings is a description of exemplary embodiments and isnot intended to represent the only embodiments through which theconcepts explained in these embodiments can be practiced. The detaileddescription includes details for the purpose of providing anunderstanding of the present invention. However, it will be apparent tothose skilled in the art that these teachings may be implemented andpracticed without these specific details.

In some instances, known structures and devices are omitted, or areshown in block diagram form focusing on important features of thestructures and devices, so as not to obscure the concept of the presentinvention.

In the embodiments of the present invention, the enhanced Node B (eNodeB or eNB) may be a terminal node of a network, which directlycommunicates with the terminal. In some cases, a specific operationdescribed as performed by the eNB may be performed by an upper node ofthe eNB. Namely, it is apparent that, in a network comprised of aplurality of network nodes including an eNB, various operationsperformed for communication with a terminal may be performed by the eNB,or network nodes other than the eNB. The term ‘eNB’ may be replaced withthe term ‘fixed station’, ‘base station (BS)’, ‘Node B’, ‘basetransceiver system (BTS),’, ‘access point (AP)’, etc. The term ‘userequipment (UE)’ may be replaced with the term ‘terminal’, ‘mobilestation (MS)’, ‘user terminal (UT)’, ‘mobile subscriber station (MSS)’,‘subscriber station (SS)’, ‘Advanced Mobile Station (AMS)’, ‘Wirelessterminal (WT)’, ‘Machine-Type Communication (MTC) device’,‘Machine-to-Machine (M2M) device’, ‘Device-to-Device(D2D) device’,wireless device, etc.

In the embodiments of the present invention, “downlink (DL)” refers tocommunication from the eNB to the UE, and “uplink (UL)” refers tocommunication from the UE to the eNB. In the downlink, transmitter maybe a part of eNB, and receiver may be part of UE. In the uplink,transmitter may be a part of UE, and receiver may be part of eNB.

Specific terms used for the embodiments of the present invention areprovided to aid in understanding of the present invention. Thesespecific terms may be replaced with other terms within the scope andspirit of the present invention.

The embodiments of the present invention can be supported by standarddocuments disclosed for at least one of wireless access systems,Institute of Electrical and Electronics Engineers (IEEE) 802, 3rdGeneration Partnership Project (3GPP), 3GPP Long Term Evolution (3GPPLTE), LTE-Advanced (LTE-A), and 3GPP2. Steps or parts that are notdescribed to clarify the technical features of the present invention canbe supported by those documents. Further, all terms as set forth hereincan be explained by the standard documents.

Techniques described herein can be used in various wireless accesssystems such as Code Division Multiple Access (CDMA), Frequency DivisionMultiple Access (FDMA), Time Division Multiple Access (TDMA), OrthogonalFrequency Division Multiple Access (OFDMA), Single Carrier-FrequencyDivision Multiple Access (SC-FDMA), ‘non-orthogonal multiple access(NOMA)’, etc. CDMA may be implemented as a radio technology such asUniversal Terrestrial Radio Access (UTRA) or CDMA2000. TDMA may beimplemented as a radio technology such as Global System for Mobilecommunications (GSM)/General Packet Radio Service (GPRS)/Enhanced DataRates for GSM Evolution (EDGE). OFDMA may be implemented as a radiotechnology such as IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE802.20, Evolved-UTRA (E-UTRA) etc. UTRA is a part of Universal MobileTelecommunication System (UMTS). 3GPP LTE is a part of Evolved UMTS(E-UMTS) using E-UTRA. 3GPP LTE employs OFDMA for downlink and SC-FDMAfor uplink. LTE-A is an evolution of 3GPP LTE.

For clarity, this application focuses on the 3GPP LTE/LTE-A system.However, the technical features of the present invention are not limitedthereto.

General System to Which the Present Invention May be Applied

FIG. 1 illustrates a schematic structure a network structure of anevolved universal mobile telecommunication system (E-UMTS) to which thepresent invention can be applied.

An E-UMTS system is an evolved version of the UMTS system. For example,the E-UMTS may be also referred to as an LTE/LTE-A system. The E-UMTS isalso referred to as a Long Term Evolution (LTE) system.

The E-UTRAN consists of eNBs, providing the E-UTRA user plane andcontrol plane protocol terminations towards the UE. The eNBs areinterconnected with each other by means of the X2 interface. The X2 userplane interface (X2-U) is defined between eNBs. The X2-U interfaceprovides non guaranteed delivery of user plane packet data units (PDUs).The X2 control plane interface (X2-CP) is defined between two neighboureNBs. The X2-CP performs following functions: context transfer betweeneNBs, control of user plane tunnels between source eNB and target eNB,transfer of handover related messages, uplink load management and thelike. Each eNB is connected to User Equipments (UEs) through a radiointerface and is connected to an Evolved Packet Core (EPC) through an S1interface. The S1 user plane interface (S1-U) is defined between the eNBand the serving gateway (S-GW). The S1-U interface provides nonguaranteed delivery of user plane PDUs between the eNB and the S-GW. TheS1 control plane interface (S1-MME) is defined between the eNB and theMME (Mobility Management Entity). The S1 interface performs followingfunctions: EPS (Enhanced Packet System) Bearer Service Managementfunction, NAS (Non-Access Stratum) Signaling Transport function, NetworkSharing Function, MME Load balancing Function and the like. The S1interface supports a many-to-many relation between MMEs/S-GWs and eNBs.

FIG. 2 illustrates the configurations of a control plane and a userplane of a radio interface protocol between the E-UTRAN and a UE in thewireless communication system to which the present invention can beapplied.

FIG. 2(a) shows the respective layers of the radio protocol controlplane, and FIG. 2(b) shows the respective layers of the radio protocoluser plane.

Referring to the FIG. 2, the protocol layers of a radio interfaceprotocol between the E-UTRAN and a UE can be divided into an L1 layer(first layer), an L2 layer (second layer), and an L3 layer (third layer)based on the lower three layers of the Open System Interconnection (OSI)reference model widely known in communication systems. The radiointerface protocol is divided horizontally into a physical layer, a datalink layer, and a network layer, and vertically into a user plane fordata transmission and a control plane for signaling.

The control plane is a passage through which control messages that a UEand a network use in order to manage calls are transmitted. The userplane is a passage through which data (e.g., voice data or Internetpacket data) generated at an application layer is transmitted. Thefollowing is a detailed description of the layers of the control anduser planes in a radio interface protocol.

The control plane is a passage through which control messages that a UEand a network use in order to manage calls are transmitted. The userplane is a passage through which data (e.g., voice data or Internetpacket data) generated at an application layer is transmitted. Thefollowing is a detailed description of the layers of the control anduser planes in a radio interface protocol.

The MAC layer of the second layer provides a service to a Radio LinkControl (RLC) layer, located above the MAC layer, through a logicalchannel The MAC layer plays a role in mapping various logical channelsto various transport channels. And, the MAC layer also plays a role aslogical channel multiplexing in mapping several logical channels to onetransport channel.

The RLC layer of the second layer supports reliable data transmission.The RLC layer performs segmentation and concatenation on data receivedfrom an upper layer to play a role in adjusting a size of the data to besuitable for a lower layer to transfer the data to a radio section. And,the RLC layer provides three kinds of RLC modes including a transparentmode (TM), an unacknowledged mode (UM) and an acknowledged mode (AM) tosecure various kinds of QoS demanded by each radio bearer (RB). Inparticular, the AM RLC performs a retransmission function throughautomatic repeat and request (ARQ) for the reliable data transfer. Thefunctions of the RLC layer may also be implemented through internalfunctional blocks of the MAC layer. In this case, the RLC layer need notbe present.

A packet data convergence protocol (PDCP) layer of the second layerperforms a header compression function for reducing a size of an IPpacket header containing relatively large and unnecessary controlinformation to efficiently transmit such an IP packet as IPv4 and IPv6in a radio section having a small bandwidth. This enables a header partof data to carry mandatory information only to play a role in increasingtransmission efficiency of the radio section. Moreover, in the LTE/LTE-Asystem, the PDCP layer performs a security function as well. Thisconsists of ciphering for preventing data interception conducted by athird party and integrity protection for preventing data manipulationconducted by a third party.

A Radio Resource Control (RRC) layer located at the bottom of the thirdlayer is defined only in the control plane and is responsible forcontrol of logical, transport, and physical channels in association withconfiguration, re-configuration, and release of Radio Bearers (RBs). TheRB is a logical path that the second layer provides for datacommunication between the UE and the E-UTRAN. To accomplish this, theRRC layer of the UE and the RRC layer of the network exchange RRCmessages. To Configure of Radio Bearers means that the radio protocollayer and the characteristic of channels are defined for certain serviceand that each of specific parameters and operating method are configuredfor certain service. The radio bearer can be divided signaling radiobearer (SRB) and data radio bearer (DRB). The SRB is used as a path fortransmission RRC messages in the control plane, and the DRB is used as apath for transmission user data in the user plane.

A Non-Access Stratum (NAS) layer located above the RRC layer performsfunctions such as session management and mobility management.

One cell of the eNB is set to use a bandwidth such as 1.25, 2.5, 5, 10or 20 MHz to provide a downlink or uplink transmission service to UEs.Here, different cells may be set to use different bandwidths.

Downlink transport channels for transmission of data from the network tothe UE include a Broadcast Channel (BCH) for transmission of systeminformation, a Paging Channel (PCH) for transmission of paging messages,and a downlink Shared Channel (DL-SCH) for transmission of user trafficor control messages. User traffic or control messages of a downlinkmulticast or broadcast service may be transmitted through DL-SCH and mayalso be transmitted through a downlink multicast channel (MCH). Uplinktransport channels for transmission of data from the UE to the networkinclude a Random Access Channel (RACH) for transmission of initialcontrol messages and an uplink SCH (UL-SCH) for transmission of usertraffic or control messages.

Logical channels, which are located above the transport channels and aremapped to the transport channels, include a Broadcast Control Channel(BCCH), a Paging Control Channel (PCCH), a Common Control Channel(CCCH), a dedicated control channel (DCCH), a Multicast Control Channel(MCCH), a dedicated traffic channel (DTCH), and a Multicast TrafficChannel (MTCH).

As an downlink physical channel for transmitting information forwardedon an downlink transport channel to a radio section between a networkand a user equipment, there is a physical downlink shared channel(PDSCH) for transmitting information of DL-SCH, a physical controlformat indicator channel (PDFICH) for indicating the number of OFDMsymbols used for transmitting a physical downlink control channel(PDCCH), a physical HARQ (hybrid automatic repeat request) indicatorchannel (PHICH) for transmitting HARQ ACK (Acknowledge)/NACK(Non-acknowledge) as response to UL transmission or a PDCCH fortransmitting such control information, as DL grant indicating resourceallocation for transmitting a Paging Channel (PCH) and DL-SCH,information related to HARQ, UL grant indicating resource allocation fortransmitting a UL-SCH and like that. As an uplink physical channel fortransmitting information forwarded on an uplink transport channel to aradio section between a network and a user equipment, there is aphysical uplink shared channel (PUSCH) for transmitting information ofUL-SCH, a physical random access channel (PRACH) for transmitting RACHinformation or a physical uplink control channel (PUCCH) fortransmitting such control information, which is provided by first andsecond layers, as HARQ ACK/NACK (Non-acknowledge), scheduling request(SR), channel quality indicator (CQI) report and the like.

The NAS state model is based on a two-dimensional model which consistsof EPS Mobility Management (EMM) states and of EPS Connection Management(ECM) states. The EMM states describe the mobility management statesthat result from the mobility management procedures e.g., Attach andTracking Area Update procedures. The ECM states describe the signalingconnectivity between the UE and the EPC.

In detail, in order to manage mobility of a UE in NAS layers positionedin control planes of the UE and an MME, an EPS mobility managementREGISTERED (EMM-REGISTERED) state and an EMM-DEREGISTERED state may bedefined. The EMM-REGISTERED state and the EMM-DEREGISTERED state may beapplied to the UE and the MME.

The UE is in the EMM deregistered state, like a state in which power ofthe UE is first turned on, and in order for the UE to access a network,a process of registering in the corresponding network is performedthrough an initial access procedure. When the access procedure issuccessfully performed, the UE and the MME transition to anEMM-REGISTERED state.

Also, in order to manage signaling connection between the UE and thenetwork, an EPS connection management CONNECTED (ECM-CONNECTED) stateand an ECM-IDLE state may be defined. The ECM-CONNECTED state and theECM-IDLE state may also be applied to the UE and the MME. The ECMconnection may include an RRC connection established between the UE anda BS and an S1 signaling connection established between the BS and theMME. The RRC state indicates whether an RRC layer of the UE and an RRClayer of the BS are logically connected. That is, when the RRC layer ofthe UE and the RRC layer of the BS are connected, the UE may be in anRRC_CONNECTED state. When the RRC layer of the UE and the RRC layer ofthe BS are not connected, the UE in an RRC_IDLE state.

Here, the ECM and EMM states are independent of each other and when theUE is in EMM-REGISTERED state this does not imply that the user plane(radio and S1 bearers) is established

In E-UTRAN RRC_CONNECTED state, network-controlled UE-assisted handoversare performed and various DRX cycles are supported. In E-UTRAN RRC_IDLEstate, cell reselections are performed and DRX is supported.

The network may recognize the presence of the UE in the ECM-CONNECTEDstate by the cell and effectively control the UE. That is, when the UEis in the ECM-CONNECTED state, mobility of the UE is managed by acommand from the network. In the ECM-CONNECTED state, the network knowsabout a cell to which the UE belongs. Thus, the network may transmitand/or receive data to or from the UE, control mobility such as handoverof the UE, and perform cell measurement on a neighbor cell.

Meanwhile, the network cannot recognize the presence of the UE in theECM-idle state and a core network (CN) manages the UE by the trackingarea, a unit greater than cell. When the UE is in the ECM-idle state,the UE performs discontinuous reception (DRX) set by the NAS using an IDuniquely assigned in a tracking region. That is, the UE may monitor apaging signal at a particular paging opportunity in every UE-specificpaging DRX cycle to receive broadcast of system information and paginginformation. Also, when the UE is in the ECM-idle state, the networkdoes not have context information of the UE.

Thus, the UE in the ECM-idle state may perform a UE-basedmobility-related procedure such as cell selection or cell reselectionwithout having to receive a command from the network. When a location ofthe UE in the ECM-idle state is changed from that known by the network,the UE may inform the network about a location thereof through atracking area update (TAU) procedure.

As described above, in order for the UE to receive a general mobilecommunication service such as voice or data, the UE needs to transitionto an ECM-CONNECTED state. The UE is in the ECM-IDLE state like the casein which power of the UE is first turned on. When the UE is successfullyregistered in the corresponding network through an initial attachprocedure, the UE and the MME transition to an ECM-CONNECTED state.Also, in a case in which the UE is registered in the network but trafficis deactivated so radio resource is not allocated, the UE is in anECM-IDLE state, and when uplink or downlink new traffic is generated inthe corresponding UE, the UE and the MME transition to an ECM-CONNECTEDstate through a service request procedure.

FIG. 3 illustrates physical channels and a view showing physicalchannels used for in the 3GPP LTE/LTE-A system to which the presentinvention can be applied.

When a UE is powered on or when the UE newly enters a cell, the UEperforms an initial cell search operation such as synchronization with aBS in step S301. For the initial cell search operation, the UE mayreceive a Primary Synchronization Channel (P-SCH) and a SecondarySynchronization Channel (S-SCH) from the BS so as to performsynchronization with the BS, and acquire information such as a cell ID.

Thereafter, the UE may receive a physical broadcast channel (PBCH) fromthe BS and acquire broadcast information in the cell. Meanwhile, the UEmay receive a Downlink Reference signal (DL RS) in the initial cellsearch step and confirm a downlink channel state.

The UE which completes the initial cell search may receive a PhysicalDownlink Control Channel (PDCCH) and a Physical Downlink Shared Channel(PDSCH) corresponding to the PDCCH, and acquire more detailed systeminformation in step S302.

Thereafter, the UE may perform a random access procedure in steps S303to S306, in order to complete the access to the BS. For the randomaccess procedure, the UE may transmit a preamble via a Physical RandomAccess Channel (PRACH) (S303), and may receive a message in response tothe preamble via the PDCCH and the PDSCH corresponding thereto (S304).In contention-based random access, a contention resolution procedureincluding the transmission of an additional PRACH (S305) and thereception of the PDCCH and the PDSCH corresponding thereto (S306) may beperformed.

The UE which performs the above-described procedure may then receive thePDCCH/PDSCH (S307) and transmit a Physical Uplink Shared Channel(PUSCH)/Physical Uplink Control Channel (PUCCH) (S308), as a generaluplink/downlink signal transmission procedure.

Control information transmitted from the UE to the BS is collectivelyreferred to as uplink control information (UCI). The UCI includes hybridautomatic repeat and request acknowledgement/negative-acknowledgement(HARQ ACK/NACK), scheduling request (SR), channel quality information(CQI), preceding matrix indicator (PMI), rank indication (RI), etc. Inthe embodiments of the present invention, CQI and/or PMI are alsoreferred to as channel quality control information.

In general, although a UCI is periodically transmitted via a PUCCH inthe LTE system, this may be transmitted through a PUSCH if controlinformation and traffic data are simultaneously transmitted. Inaddition, a UCI may be aperiodically transmitted via a PUSCH accordingto a network request/instruction.

FIG. 4 is a diagram showing the structure of a radio frame used in a3GPP LTE system to which the present invention can be applied.

In a cellular OFDM radio packet communication system, uplink/downlinkdata packet transmission is performed in subframe units and one subframeis defined as a predetermined duration including a plurality of OFDMsymbols. The 3GPP LTE standard supports a type-1 radio frame structureapplicable to frequency division duplex (FDD) and a type-2 radio framestructure applicable to time division duplex (TDD). According to the FDDscheme, the UL transmission and the DL transmission are performed byoccupying different frequency bandwidths. According to the TDD scheme,the UL transmission and the DL transmission are performed on respectivetimes different from each other while occupying the same frequencybandwidth. The channel response in the TDD scheme is substantiallyreciprocal. This signifies that the DL channel response and the ULchannel response are about the same in a given frequency domain.Accordingly, there is a merit that the DL channel response can beobtained from the UL channel response in wireless communication systemsbased on the TDD. In the TDD scheme, since entire frequency bandwidth istimely divided in the UL transmission and the DL transmission, the DLtransmission by an eNB and the UL transmission by a UE may not beperformed simultaneously. In the TDD system in which the UL transmissionand the DL transmission are distinguished by a unit of subframe, the ULtransmission and the DL transmission are performed in differentsubframes.

FIG. 4(a) shows the structure of the type-1 radio frame. A downlinkradio frame includes 10 subframes and one subframe includes two slots ina time domain. A time required to transmit one subframe is referred toas a transmission time interval (TTI). For example, one subframe has alength of 1 ms and one slot has a length of 0.5 ms. One slot includes aplurality of OFDM symbols in a time domain and includes a plurality ofresource blocks (RBs) in a frequency domain. In the 3GPP LTE system,since OFDMA is used in the downlink, an OFDM symbol indicates one symbolperiod. The OFDM symbol may be referred to as an SC-FDMA symbol orsymbol period. A RB as a resource allocation unit may include aplurality of consecutive subcarriers in one slot.

The number of OFDM symbols included in one slot may be changed accordingto the configuration of cyclic prefix (CP). CP includes an extended CPand a normal CP. For example, if OFDM symbols are configured by thenormal CP, the number of OFDM symbols included in one slot may be 7. IfOFDM symbols are configured by the extended CP, since the length of oneOFDM symbol is increased, the number of OFDM symbols included in oneslot is less than the number of OFDM symbols in case of the normal CP.In case of the extended CP, for example, the number of OFDM symbolsincluded in one slot may be 6. In the case where a channel state isunstable, such as the case where a UE moves at a high speed, theextended CP may be used in order to further reduce inter-symbolinterference.

In case of using the normal CP, since one slot includes seven OFDMsymbols, one subframe includes 14 OFDM symbols. At this time, a maximumof three first OFDM symbols of each subframe may be allocated to aphysical downlink control channel (PDCCH) and the remaining OFDM symbolsmay be allocated to a physical downlink shared channel (PDSCH).

FIG. 4(b) shows the structure of the type-2 radio frame. The type-2radio frame includes two half frames and each half frame includes fivesubframes, a downlink pilot time slot (DwPTS), a guard period (GP) andan uplink pilot time slot (UpPTS). From among these, one subframeincludes two slots. The DwPTS is used for initial cell search,synchronization or channel estimation of a UE. The UpPTS is used forchannel estimation of a BS and uplink transmission synchronization of aUE. The GP is used to eliminate interference generated in the uplink dueto multi-path delay of a downlink signal between the uplink and thedownlink.

The structure of the radio frame is only exemplary and the number ofsubframes included in the radio frame, the number of slots included inthe subframe, or the number of symbols included in the slot may bevariously changed.

FIG. 5 shows an example of a resource grid for one downlink slot in thewireless communication system to which the present invention can beapplied.

Referring to the FIG. 5, the downlink slot includes a plurality of OFDMsymbols in a time domain. It is described herein that one downlink slotincludes 7 OFDMA symbols and one resource block includes 12 subcarriersfor exemplary purposes only, and the present invention is not limitedthereto.

Each element on the resource grid is referred to as a resource element,and one resource block includes 12×7 resource elements. The resourceelement on the resource grid may be identified by an index pair (k, l)in the slot. Here, k (k=0, . . . , N_(RB)×12−1) denotes an index ofsubcarrier in the frequency domain, and l (l=0, . . . , 6) denotes anindex of symbol in the time domain. The number NDL of resource blocksincluded in the downlink slot depends on a downlink transmissionbandwidth determined in a cell.

FIG. 6 shows a structure of a downlink subframe in the wirelesscommunication system to which the present invention can be applied.

Referring to the FIG. 6, a maximum of three OFDM symbols located in afront portion of a first slot in a subframe correspond to a controlregion to be assigned with control channels. The remaining OFDM symbolscorrespond to a data region to be assigned with physical downlink sharedchannels (PDSCHs).

Examples of downlink control channels used in the 3GPP LTE include aphysical control format indicator channel (PCFICH), a physical downlinkcontrol channel (PDCCH), a physical hybrid-ARQ indicator channel(PHICH), etc. The PCFICH transmitted in a 1st OFDM symbol of a subframecarries information regarding the number of OFDM symbols (i.e., a sizeof a control region) used for transmission of control channels in thesubframe. Control information transmitted over the PDCCH is referred toas downlink control information (DCI). The DCI transmits uplink resourceassignment information, downlink resource assignment information, anuplink transmit power control (TPC) command for any UE groups, etc. ThePHICH carries an acknowledgement (ACK)/not-acknowledgement (NACK) signalfor an uplink hybrid automatic repeat request (HARQ). That is, theACK/NACK signal for uplink data transmitted by a UE is transmitted overthe PHICH.

A BS determines a PDCCH format according to DCI to be transmitted to aUE, and attaches a cyclic redundancy check (CRC) to control information.The CRC is masked with a unique identifier (referred to as a radionetwork temporary identifier (RNTI)) according to an owner or usage ofthe PDCCH. If the PDCCH is for a specific UE, a unique identifier (e.g.,cell-RNTI (C-RNTI)) of the UE may be masked to the CRC. Alternatively,if the PDCCH is for a paging message, a paging indication identifier(e.g., paging-RNTI (P-RNTI)) may be masked to the CRC. If the PDCCH isfor system information, a system information identifier (e.g., systeminformation-RNTI (SI-RNTI)) may be masked to the CRC. To indicate arandom access response that is a response for transmission of a randomaccess preamble of the UE, a random access-RNTI (RA-RNTI) may be maskedto the CRC.

FIG. 7 shows a structure of an uplink subframe in the wirelesscommunication system to which the present invention can be applied.

Referring to the FIG. 7, the uplink subframe can be divided in afrequency domain into a control region and a data region. The controlregion is allocated with a physical uplink control channel (PUCCH) forcarrying uplink control information. The data region is allocated with aphysical uplink shared channel (PUSCH) for carrying user data. In caseof being indicated from higher layer, UE can simultaneously transmit thePUCCH and the PUSCH.

The PUCCH for one UE is allocated to an RB pair in a subframe. RBsbelonging to the RB pair occupy different subcarriers in respective twoslots. This is called that the RB pair allocated to the PUCCH isfrequency-hopped in a slot boundary.

Physical Downlink Control Channel (PDCCH)

The control information transmitted through the PDCCH is referred to asa downlink control indicator (DCI). In the PDCCH, a size and use of thecontrol information are different according to a DCI format. Inaddition, a size of the control information may be changed according toa coding rate.

Table 1 represents the DCI according to the DCI format.

TABLE 1 DCI format Objectives 0 Scheduling of PUSCH 1 Scheduling of onePDSCH codeword 1A Compact scheduling of one PDSCH codeword 1BClosed-loop single-rank transmission 1C Paging, RACH response anddynamic BCCH 1D MU-MIMO 2 Scheduling of rank-adapted closed-loop spatialmultiplexing mode 2A Scheduling of rank-adapted open-loop spatialmultiplexing mode 3 TPC commands for PUCCH and PUSCH with 2bit poweradjustments 3A TPC commands for PUCCH and PUSCH with single bit poweradjustments 4 The scheduling of PUSCH in one UL cell with multi-antennaport transmission mode

Referring to Table 1, the DCI format includes format 0 for the PUSCHscheduling, format 1 for scheduling of one PDSCH codeword, format 1A forcompact scheduling of one PDSCH codeword, format 1C for very compactscheduling of the DL-SCH, format 2 for PDSCH scheduling in a closed-loopspatial multiplexing mode, format 2A for PDSCH scheduling in anopen-loop spatial multiplexing mode, formats 3 and 3A for transmitting atransmission power control (TPC) command for a UL channel, and format 4for PUSCH scheduling within one UL cell in a multiple antenna porttransmission mode.

DCI format 1A may be used for PDSCH scheduling whichever transmissionmode is configured to a UE.

Such DCI formats may be independently applied to each UE, and the PDCCHsof several UEs may be simultaneously multiplexed in one subframe. ThePDCCH is comprised of an aggregation of one or a few continuous controlchannel elements (CCEs). The CCE is a logical allocation unit used forproviding a coding rate according to a state of radio channel to thePDCCH. The CCE is referred to as a unit that corresponds to nine sets ofresource element group (REG) which is comprised of four resourceelements. An eNB may use {1, 2, 4, 8} CCEs for constructing one PDCCHsignal, and this {1, 2, 4, 8} is called a CCE aggregation level. Thenumber of CCE used for transmitting a specific PDCCH is determined bythe eNB according to the channel state. The PDCCH configured accordingto each UE is mapped with being interleaved to a control channel regionof each subframe by a CCE-to-RE mapping rule. A location of the PDCCHmay be changed according to the number of OFDM symbols for the controlchannel, the number of PHICH group, a transmission antenna, a frequencyshift, etc.

As described above, a channel coding is independently performed for thePDCCH of each multiplexed UE, and the cyclic redundancy check (CRC) isapplied. By masking each UE ID to CRC, the UE may receive its PDCCH.However, in the control region allocated in a subframe, the eNB does notprovide information on where the PDCCH that corresponds to the UE is.Since the UE is unable to know on which position its PDCCH istransmitted with which CCE aggregation level and DCI format in order toreceive the control channel transmitted from the eNB, the UE finds itsown PDCCH by monitoring a set of PDCCH candidates in a subframe. This iscalled a blind decoding (BD). The blind decoding may also be called ablind detection or a blind search. The blind decoding signifies a methodof verifying whether the corresponding PDCCH is its control channel bychecking CRC errors, after the UE de-masks its UE ID in CRC part.

Hereinafter, the information transmitted through DCI format 0 will bedescribed.

FIG. 8 illustrates a structure of DCI format 0 in the wirelesscommunication system to which the present invention can be applied.

DCI format 0 is used for scheduling the PUSCH in one UL cell.

Table 2 represents information transmitted via DCI format 0.

TABLE 2 Format 0 (Release 8) Format 0 (Release 10) Carrier Indicator(CIF) Flag for format 0/format 1A Flag for format 0/format 1Adifferentiation differentiation Hopping flag (FH) Hopping flag (FH)Resource block assignment Resource block assignment (RIV) (RIV) MCS andRV MCS and RV NDI (New Data Indicator) NDI (New Data Indicator) TPC forPUSCH TPC for PUSCH Cyclic shift for DM RS Cyclic shift for DM RS ULindex (TDD only) UL index (TDD only) Downlink Assignment Index DownlinkAssignment Index (DAI) (DAI) CSI request (1 bit) CSI request (1 or 2bits: 2 bit is for multi carrier) SRS request Resource allocation type(RAT)

Referring to FIG. 8 and Table 2, the information transmitted via DCIformat 0 is as follows.

1) Carrier indicator—Includes 0 or 3 bits.

2) Flag for DCI format 0/1A differentiation—Includes 1 bit, a value of 0indicates DCI format 0 and a value of 1 indicates DCI format 1A.

3) Frequency hopping flag—Includes 1 bit. In this field, a mostsignificant bit (MSB) of resource allocation may be used formulti-cluster allocation.

4) Resource block assignment and hopping resource assignment—Includes┌log₂ (N_(RB) ^(DL)(N_(RB) ^(DL)+1)/2)┐ bits.

Herein, in case of PUSCH hopping in single-cluster allocation, in orderto acquire a value of ñ_(PRB)(i) NUL_hop MSBs are used. (┌log₂(N_(RB)^(UL)(N_(RB) ^(UL)+1)/2)┐−N_(UL) _(_) _(hop)) bits provide resourceallocation of a first slot within an uplink subframe. In addition, ifPUSCH hopping is not present in single-cluster allocation, (┌log₂(N_(RB)^(UL)(N_(RB) ^(UL)+1)/2)┐) bits provide resource allocation within anuplink subframe. In addition, if PUSCH hopping is not present inmulti-cluster allocation, resource allocation information is obtainedfrom concatenation between the frequency hopping flag field and resourceblock assignment and hopping resource assignment field and

$\left\lceil {\log_{2}\left( \begin{pmatrix}\left\lceil {{N_{RB}^{UL}/P} + 1} \right\rceil \\4\end{pmatrix} \right)} \right\rceil$bits provide resource allocation within an uplink subframe. At thistime, the P value is determined by the number of downlink resourceblocks.

5) Modulation and coding scheme (MCS)—Includes 5 bits.

6) New data indicator—Includes 1 bit.

7) Transmit power control (TPC) command for PUSCH—Includes 2 bits.

8) Index of orthogonal cover/orthogonal cover code (OC/OCC) and cyclicshift for demodulation reference signal (DMRS)—Includes 3 bits.

9) Uplink Index—Includes 2 bits. This field is present only in TDDoperation according to uplink-downlink configuration 0.

10) Downlink assignment index (DAI)—Includes 2 bits. This field ispresent only in TDD operation according to uplink-downlinkconfigurations 1 to 6.

11) Channel state information (CSI) request—Includes 1 or 2 bits.Herein, a 2-bit field is only applied to the case in which the DCI ismapped to the UE, for which one or more downlink cells are configured,by the C-RNTI in a UE-specific manner

12) Sounding reference signal (SRS) request—Includes 0 or 1 bit. Thisfield is present only in the case in which a scheduled PUSCH is mappedin a UE-specific manner by the C-RNTI.

13) Multi-cluster flag—Includes 1 bit.

If the number of information bits in DCI format 0 is less than thepayload size (including added padding bits) of DCI format 1A, 0 isappended to DCI format 0 such that the number of information bitsbecomes equal to the payload size of DCI format 1A.

PUCCH(Physical Uplink Control Channel)

The PUCCH carries various sorts of uplink control information (UCI)according to format as follows.

-   -   SR (Scheduling Request): This is information used for requesting        the UL-SCH resource. This information is transmitted using an        on-off keying (OOK) method.    -   HARQ ACK/NACK: This is a response signal for DL data packet on a        PDSCH. This information represents whether the DL data packet is        successfully received. One bit of ACK/NACK is transmitted in        response to a single DL codeword and two bits of ACK/NACK are        transmitted in response to two DL codewords.    -   CSI (Channel State Information): This is feedback information        for a DL channel. The CSI may include at least one of a channel        quality indicator (CQI), a rank indicator (RI), a precoding        matrix indicator (PMI) and a precoding type indicator (PTI).        Hereinafter, this will be referred to ‘CQI’ as a common term for        the convenience of description.

The PUCCH may be modulated by using a binary phase shift keying (BPSK)technique and a quadrature phase shift keying (QPSK) technique. Controlinformation for a plurality of UEs may be transmitted through the PDCCH.In case of performing code division multiplexing (CDM) to distinguishsignal of each of the UEs, constant amplitude zero autocorrelation(CAZAC) sequence is mostly used. Since the CAZAC sequence hascharacteristics of maintaining a fixed amplitude in a time domain and afrequency domain, the CAZAC has characteristics proper to increasecoverage by lowering a peak-to-average power ratio (PAPR) or a cubicmetric (CM) of a UE. In addition, the ACK/NACK information for DL datatransmission transmitted through the PDCCH is covered by using anorthogonal sequence or an orthogonal cover (OC).

Additionally, control information transmitted on the PUCCH may bedistinguished by using a cyclically shifted sequence that has differentcyclic shift (CS) values. The cyclically shifted sequence may begenerated by shifting cyclically a base sequence by as much as apredetermined cyclic shift amount. The cyclic shift amount is indicatedby a CS index. The number of available cyclic shift may be changedaccording to delay spread of a channel. Various sorts of sequence may beused as the basic sequence, and the CAZAC sequence described above is anexample.

In addition, the quantity of control information that can be transmittedby a UE in a subframe may be determined depending on the number ofSC-FDMA symbols (i.e., signifies SC-FDMA symbols other than SC-FDMAsymbols used for reference signal (RS) transmission for detectingcoherent detection of the PUCCH, but except for the last SC-FDMA symbolin a subframe in which a sounding reference signal (SRS) is configured).

The PUCCH may be defined by seven sorts of different formats dependingon the control information, a modulation technique, a quantity of thecontrol information, etc. which is transmitted, and the property ofuplink control information (UCI) transmitted according to each of thePUCCH formats may be summarized as Table 1 below.

TABLE 3 PUCCH Format Uplink Control Information(UCI) Format 1 SchedulingRequest(SR)(unmodulated waveform) Format 1a 1-bit HARQ ACK/NACKwith/without SR Format 1b 2-bit HARQ ACK/NACK with/without SR Format 2CQI (20 coded bits) Format 2 CQI and 1- or 2-bit HARQ ACK/NACK (20 bits)for extended CP only Format 2a CQI and 1-bit HARQ ACK/NACK (20 + 1 codedbits) Format 2b CQI and 2-bit HARQ ACK/NACK (20 + 2 coded bits) Format 3HARQ ACK/NACK, SR, CSI (48 coded bits)

Referring to Table 3, PUCCH format 1 is used for a single transmissionof a scheduling request (SR). Wave forms which are not modulated areapplied to the single transmission of SR, and this will be describedbelow in detail.

PUCCH format 1a or 1b is used for transmitting HARQacknowledgement/non-acknowledgement (ACK/NACK). When the HARQ ACK/NACKis solely transmitted in an arbitrary subframe, PUCCH format 1a or 1bmay be used. Or, the HARQ ACK/NACK and the SR may be transmitted in asame subframe by using PUCCH format 1a or 1b.

PUCCH format 2 is used for transmitting the CQI, and PUCCH format 2a or2b is used for transmitting the CQI and the HARQ ACK/NACK. In case of anextended CP, PUCCH format 2 may also be used for transmitting the CQIand the HARQ ACK/NACK.

PUCCH format 3 is used for carrying an encoded UCI of 48 bits. PUCCHformat 3 may carry the HARQ ACK/NACK for a plurality of serving cells,the SR (if existed) and the CSI report for a serving cell.

FIG. 9 illustrates an example of a formation that PUCCH formats aremapped to the PUCCH regions of the UL physical resource blocks in thewireless communication system to which the present application can beapplied.

A PUCCH for a UE is allocated to an RB pair in a subframe. The RBsbelonging to the RB pair occupy different subcarriers in each of a firstslot and a second slot. A frequency occupied by RBs belonged in the RBpair allocated to the PUCCH is changed based on a slot boundary. This isexpressed that the RB pair allocated to the PUCCH is frequency-hopped inthe slot boundary. A UE transmits UL control information throughdifferent subcarriers according to time, thereby obtaining a frequencydiversity gain.

In FIG. 9, N_(RB) ^(uL) represents the number of resource block in UL,and 0, 1, . . . , N_(RB) ^(uL)−1 signifies given number of the physicalresource block. Basically, the PUCCH is mapped to both edges of the ULfrequency blocks. As shown in FIG. 9, PUCCH formats 2/2a/2b are mappedto the respective PUCCH regions marked by m=0 and 1, and this may berepresented as PUCCH formats 2/2a/2b are mapped to the resource blockslocated at band edges. In addition, PUCCH formats 2/2a/2b and PUCCHformats 1/1a/1b are mixedly mapped to the PUCCH region marked by m=2.Next, PUCCH formats 1/1a/1b may be mapped to the PUCCH regions marked bym=3, 4 and 5. The number N_(RB) ⁽²⁾ of PUCCH RBs usable by PUCCH formats2/2a/2b may be indicated by the UEs within a cell by broadcastingsignaling.

Table 4 represents modulation schemes according to the PUCCH format andnumber of bits per subframe. In Table 4, PUCCH formats 2a and 2bcorrespond to the case of normal cyclic shift.

TABLE 4 PUCCH Modulation Number of bits per format scheme subframe,M_(bit) 1 N/A N/A 1a BPSK 1 1b QPSK 2 2 QPSK 20 2a QPSK + BPSK 21 2bQPSK + QPSK 22 3 QPSK 48

Table 5 represents the number of symbols of PUCCH demodulation referencesignal per slot according to the PUCCH format.

TABLE 5 PUCCH format Normal cyclic prefix Extended cyclic prefix 1, 1a,1b 3 2 2, 3 2 1 2a, 2b 2 N/A

Table 6 represents SC-FDMA symbol location of the PUCCH demodulationreference signal according to the PUCH format. In Table 6, l representsa symbol index.

TABLE 6 Set of values for l PUCCH format Normal cyclic prefix Extendedcyclic prefix 1, 1a, 1b 2, 3, 4 2, 3 2, 3 1, 5 3 2a, 2b 1, 5 N/A

Hereinafter, PUCCH formats 2/2a/2b will be described.

PUCCH formats 2/2a/2b are used for CQI feedback (or ACK/NACKtransmission together with the CQI feedback) for DL transmission. Inorder for the CQI to be transmitted with the ACK/NACK may be transmittedwith being embedded in the CQI RS (in case of a normal CP), ortransmitted with the CQI and the ACK/NACK being joint coded (in case ofan extended CP).

FIG. 10 shows a structure of CQI channel in case of a normal CP in thewireless communication system to which the present invention can beapplied.

Among SC-FDMA symbols 0 to 6 in a slot, SC-FDMA symbols 1 to 5 (a secondand a sixth symbols) are used for transmitting demodulation referencesignal (DMRS), and the CQI information may be transmitted in theremainder SC-FDMA symbols. Meanwhile, in case of the extended CP, oneSC-FDMA symbol (SC-FDMA symbol 3) is used for transmitting the DMRS.

In PUCCH formats 2/2a/2b, the modulation by the CAZAC sequence issupported, and the QPSK modulated symbol is multiplied by the CAZACsequence of length 12. The cyclic shift (CS) of sequence may be changedbetween symbols and slots. An orthogonal covering is used for the DMRS.

In two SC-FDMA symbols which are three SC-FDMA symbol intervals fromseven SC-FDMA symbols included in a slot, the reference signal (DMRS) iscarried, and in the remainder five SC-FDMA symbols, the CQI informationis carried. In order to support a high speed UE, two RSs are used in aslot. In addition, the respective UEs are distinguished by using thecyclic shift (CS) sequence. The CQI information symbols are transmittedwith being modulated to whole SC-FDMA symbol, and the SC-FDMA symbolincludes one sequence. That is, the UE transmits the CQI with beingmodulated to each sequence.

The number of symbols which may be transmitted to one TTI is 10, and themodulation of the CQI information is also defined to the QPSK. Frontfive symbols are transmitted in a first slot, and the remainder fivesymbols are transmitted in a second slot. Since the CQI value of 2 bitsmay be carried in case of using the QPSK mapping for the SC-FDMA symbol,the CQI value of 10 bits may be carried in one slot. Accordingly, theCQI value of maximum 20 bits may be carried in one subframe. In order tospread the CQI information in a frequency domain, a frequency domainspread code is used.

As the frequency domain spread code, the CAZAC sequence of length 12(e.g., ZC sequence) may be used. Each control channel may bedistinguished by applying the CAZAC sequence that has different cyclicshift values. An inverse fast Fourier transform is performed for the CQIinformation which is spread in the frequency domain.

By the cyclic shifts that have twelve equivalent intervals, twelvedifferent UEs may be orthogonally multiplexed on the same PUCCH RB. Incase of a normal CP, the DMRS sequence on SC-FDMA symbol 1 and 5 (onSC-FDMA symbol 3 in case of an extended CP) is similar to the CQI signalsequence on the frequency domain, but the modulation similar to that ofthe CQI information is not applied.

A UE may be semi-statically configured to report different CQI, PMI andRI types periodically on the PUCCH resources indicated by the PUCCHresource indexes n_(PUCCH) ^((1,{tilde over (p)})), n_(PUCCH)^((2,{tilde over (p)})), n_(PUCCH) ^((3,{tilde over (p)})) by a higherlayer signaling. Herein, the PUCCH resource index n_(PUCCH)^((2,{tilde over (p)})) is information that indicates the PUCCH regionused for transmitting PUCCH formats 2/2a/2b and cyclic shift (CS) to beused.

Table 7 represents an orthogonal sequence (OC) [w^(({tilde over (p)}))(0) . . . w ^(({tilde over (p)}))(N_(RS)^(PUCCH)−1)] or RS in PUCCH formats 2/2a/2b/3.

TABLE 7 Normal cyclic prefix Extended cyclic prefix [1 1] [1]

Next, PUCCH formats 1/1a/1b will be described below.

FIG. 11 shows a structure of ACK/NACK in case of a normal CP in thewireless communication system to which the present invention can beapplied.

A confirmation response information (in a state of not scrambled) of 1bit or 2 bits may be represented as a HARQ ACK/NACK modulation symbolusing the BPSK and QPSK modulation techniques, respectively. Anaffirmative confirmation response (ACK) may be encoded as ‘1’, and anegative confirmation response (NACK) may be encoded as ‘0’.

When transmitting a control signal in an allocated bandwidth, twodimensional spread is applied in order to increase a multiplexingcapacity. That is, a spread in frequency domain and a spread in timedomain are simultaneously applied in order to increase the number of UEor the number of control channel that can be multiplexed.

In order to spread an ACK/NACK signal in frequency domain, a frequencydomain sequence is used as a basic sequence. As the frequency domainsequence, Zadoff-Chu (ZC) sequence which is one of constant amplitudezero autocorrelation waveform sequences may be used.

That is, in PUCCH format 1a/1b, the symbol modulated using the BPSK orthe QPSK modulation scheme is multiplied by the CAZAC sequence (e.g.,the ZC sequence) of length 12. For example, the result of the CAZACsequence r(n) (n=0, 1, 2, . . . , N−1) of length N modulated tomodulation symbol d(0) is y(0), y(1), y(2), . . . , y(N−1). The symbolsy(0), y(1), y(2), . . . , y(N−1) may be referred to as block of symbols.

Like this, different cyclic shifts (CS) are applied to the Zadoff Chu(ZC) sequence which is a basic sequence, and multiplexing of differentUEs or different control channels may be applied. The number of CSresources supported by SC-FDMA symbol which is for PUCCH RBs in the HARQACK/NACK transmission is setup by a cell-specific higher layer signalingparameter(Δ_(shift) ^(PUCCH)).

After multiplying the CAZAC sequence to the modulation symbol, theblock-wise spread using an orthogonal sequence is applied. That is, theACK/NACK signal spread in a frequency domain is spread in a time domainby using an orthogonal spreading code. As for the orthogonal spreadingcode (or the orthogonal cover sequence or an orthogonal cover code(OCC)), a Walsh-Hadamard sequence or a Discrete Fourier Transform (DFT)sequence may be used. For example, the ACK/NACK signal may be spread byusing the orthogonal sequence (w0, w1, w2, w3) of length 4 for foursymbols. In addition, an RS is also spread through the orthogonalsequence of length 3 or length 2. This is referred to as an orthogonalcovering (OC).

As for the CDM of ACK/NACK information or demodulation reference signal,an orthogonal covering such as a Walsh code, a DFT matrix, etc. may beused.

The DFT matrix is comprised of square matrixes, and constructed as asize of N×N (N is a natural number).

The DFT matrix may be defined as Equation 1.

$\begin{matrix}{W = \left( \frac{\omega^{jk}}{\sqrt{N}} \right)_{j,{k = 0},\ldots\mspace{14mu},{N - 1}}} & \left\lbrack {{Equation}\mspace{14mu} 1} \right\rbrack\end{matrix}$

Also, the DFT matrix may be represented as a matrix of Equation 2 belowwhich is equivalent to Equation 1.

$\begin{matrix}{{W = {\frac{1}{\sqrt{N}}\begin{bmatrix}1 & 1 & 1 & 1 & \ldots & 1 \\1 & \omega & \omega^{2} & \omega^{3} & \ldots & \omega^{N - 1} \\1 & \omega^{2} & \omega^{4} & \omega^{6} & \ldots & \omega^{2{({N - 1})}} \\1 & \omega^{3} & \omega^{6} & \omega^{9} & \ldots & \omega^{3{({N - 1})}} \\\vdots & \vdots & \vdots & \vdots & \ddots & \vdots \\1 & \omega^{N - 1} & \omega^{2{({N - 1})}} & \omega^{3{({N - 1})}} & \ldots & \omega^{{({N - 1})}{({N - 1})}}\end{bmatrix}}},} & \left\lbrack {{Equation}\mspace{14mu} 2} \right\rbrack\end{matrix}$

In Equation 2,

$\omega = e^{- \frac{2\pi\; i}{N}}$signifies a primitive Nth root of unity.

The DFT matrix of 2 points, 4 points and 8 points correspond toEquations 3, 4 and 5 below.

$\begin{matrix}{\frac{1}{\sqrt{2}}\begin{bmatrix}1 & 1 \\1 & {- 1}\end{bmatrix}} & \left\lbrack {{Equation}\mspace{14mu} 3} \right\rbrack \\{W = {\frac{1}{\sqrt{4}}\begin{bmatrix}1 & 1 & 1 & 1 \\1 & {- i} & {- 1} & i \\1 & {- 1} & 1 & {- 1} \\1 & i & {- 1} & {- i}\end{bmatrix}}} & \left\lbrack {{Equation}\mspace{14mu} 4} \right\rbrack \\{W = {\frac{1}{\sqrt{8}}\begin{bmatrix}\omega^{0} & \omega^{0} & \omega^{0} & \ldots & \omega^{0} \\\omega^{0} & \omega^{1} & \omega^{2} & \ldots & \omega^{7} \\\omega^{0} & \omega^{2} & \omega^{4} & \ldots & \omega^{14} \\\omega^{0} & \omega^{3} & \omega^{6} & \ldots & \omega^{21} \\\omega^{0} & \omega^{4} & \omega^{8} & \ldots & \omega^{28} \\\omega^{0} & \omega^{5} & \omega^{10} & \ldots & \omega^{35} \\\vdots & \vdots & \vdots & \ddots & \vdots \\\omega^{0} & \omega^{7} & \omega^{14} & \ldots & \omega^{49}\end{bmatrix}}} & \left\lbrack {{Equation}\mspace{14mu} 5} \right\rbrack\end{matrix}$

In case of a normal CP, in SC-FDMA symbols that are series of 3 middleparts out of 7 SC-FDMA symbols included in a slot, the reference signal(RS) is carried, and in the rest 4 SC-FDMA symbols, the ACK/NACK signalis carried. Meanwhile, in case of an extended CP, the RS may be carriedin two consecutive symbols of the middle parts. The number and locationof symbols used for the RS may be changed according to a controlchannel, and the number and location of symbols used for the ACK/NACKsignal related may be changed according to the control channel as well.

For normal ACK/NACK information, the Walsh-Hadamard sequence havinglength 4 is used, and for shortened ACK/NACK information and thereference signal, a DFT of length 3 is used.

For the reference signal of an extended CP case, the Walsh-Hadamardsequence having length 2 is used.

Table 8 represents an orthogonal sequence of length 4 [w(0) . . .w(N_(SP) ^(PUCCH)−1)] for PUCCH format 1a/1b.

TABLE 8 Sequence index Orthogonal sequences n_(oc)^(({tilde over (p)}))(n_(s)) [w(0) . . . w(N_(SF) ^(PUCCH) − 1)] 0 [+1+1 +1 +1] 1 [+1 −1 +1 −1] 2 [+1 −1 −1 +1]

Table 9 represents an orthogonal sequence of length 3 [w(0) . . .w(N_(SF) ^(PUCCH)−1)] for PUCCH format 1a/1b.

TABLE 9 Sequence index Orthogonal sequences n_(oc)^(({tilde over (p)}))(n_(s)) [w(0) . . . w(N_(SF) ^(PUCCH) − 1)] 0 [1 11] 1 [1 e^(j2π/3) e^(j4π/3)] 2 [1 e^(j4π/3) e^(j2π/3)]

Table 10 represents an orthogonal sequence [w ^(({tilde over (p)}))(0) .. . w ^(({tilde over (p)}))(N_(RS) ^(PUCCH)−1)] for the RS in PUCCHformat 1/1a/1b.

Sequence index Normal cyclic Extended cyclic n _(oc)^(({tilde over (p)}))(n_(s)) prefix prefix 0 [1 1 1] [1 1] 1 [1e^(j2π/3) e^(j4π/3)] [1 −1] 2 [1 e^(j4π/3) e^(j2π/3)] N/A

As described above, by using the CS resource in the frequency domain andthe OC resource in the time domain, numerous UEs may be multiplexed in acode division multiplexing (CDM) method. That is, the ACK/NACKinformation and the RS of a great number of UEs may be multiplexed onthe same PUCCH RB.

For the time domain spreading CDM like this, the number of extendedcodes that are supported for the ACK/NACK information is limited by thenumber of RS symbols. That is, since the number of SC-FDMA symbols inthe RS transmission is less than the number of SC-FDMA symbols in theACK/NACK information transmission, the multiplexing capacity of RS issmaller than the multiplexing capacity of ACK/NACK information.

For example, in case of a normal CP, the ACK/NACK information may betransmitted in four symbols. In case of an extended CP, three orthogonalspreading codes, not four, may be used. This is because the number of RStransmission symbols is limited to three, and three orthogonal spreadingcodes only may be used for the RS.

In case that three symbols in one slot are used for the RS transmissionand four symbols are used for the ACK/NACK information transmission inthe subframe of a normal CP, for example, if six cyclic shifts (CSs) canbe used in the frequency domain and three orthogonal covering (OC)resources can be used in the time domain, the HARQ confirmation responsefrom total 18 different UEs may be multiplexed in one PUCCH RB. If twosymbols in one slot of a subframe of the extended CP are used for the RStransmission and four symbols are used for the ACK/NACK informationtransmission, for example, if six cyclic shifts (CSs) can be used in thefrequency domain and two orthogonal covering (OC) resources can be usedin the time domain, the HARQ confirmation response from total 12different UEs may be multiplexed in the PUCCH RB.

Subsequently, PUCCH format 1 will be described. The schedule request(SR) is transmitted in a way of a UE being requested to be scheduled ora way of not being requested. The SR channel reuses the ACK/NACK channelstructure in PUCCH format 1a/1b, and is configured in on-off keying(OOK) method based on an ACK/NACK channel design. In the SR, thereference signal is not transmitted. Accordingly, in the normal CP, thesequence of length 7 is used, and in the extended CP, the sequence oflength 6 is used. For the SR and the ACK/NACK, different cyclic shiftsor orthogonal covers may be allocated.

FIG. 12 illustrates a method for multiplexing the ACK/NACK and the SR inthe wireless communication system to which the present invention can beapplied.

The structure of SR PUCCH format 1 is identical to the structure ofACK/NACK PUCCH format 1a/1b illustrated in FIG. 12.

The SR is transmitted by using the on-off keying (KOO) method.Particularly, the UE transmits the SR having a modulation symbol d(0)=1to request the PUSCH resource (a positive SR), and in case of notrequesting the scheduling (a negative SR), nothing is transmitted. Asthe PUCCH structure for the ACK/NACK is reused for the SR, differentPUCCH resource index (that is, a combination of different CS andorthogonal code) within a same PUCCH region may be allocated to the SR(PUCCH format 1) or to the HARQ ACK/NACK (PUCCH format 1a/1b). The PUCCHresource index that is going to be used by the UE for the SRtransmission may be set by the UE-specific higher layer signaling.

In case that the UE is required to transmit the positive SR in thesubframe in which the CQI transmission is scheduled, CQI is dropped andthe SR only may be transmitted. Similarly, if a case is occurred thatthe SR and the SRS should be transmitted at the same time, the UE dropsthe CQI rather may transmit the SR only.

In case that the SR and the ACK/NACK are occurred in the same subframe,the UE transmits the ACK/NACK on the SR PUCCH resource that is allocatedfor the positive SR. In the meantime, in case of the negative SR, the UEtransmits the ACK/NACK on the allocated ACK/NACK resource.

FIG. 12 illustrates a property mapping for the simultaneous transmissionof the ACK/NACK and the SR. In particular, it illustrates that the NACK(or, in case of 2 MIMO codewords, NACK, NACK) is modulated to map to +1.Accordingly, it is processed as NACK when a discontinuous transmission(DTX) is occurred.

For the SR and persistent scheduling, the ACK/NACK resource consistingof a CS, an OC, and a physical resource block (PRB) may be allocated tothe UE through the radio resource control (RRC). Meanwhile, for thedynamic ACK/NACK transmission and non-persistent scheduling, theACK/NACK resource may be allocated to the UE implicitly through thelowest CCE index of the PDCCH corresponding to the PDSCH.

In case of requiring resources for the UL data transmission, the UE maytransmit the SR. That is, the SR transmission is triggered by an event.

The SR PUCCH resource is configured by a higher layer signaling except acase that the SR is transmitted with the HARQ ACK/NACK by using PUCCHformat 3. That is, it is configured by a SchedulingRequestConfiginformation element that is transmitted through the radio resourcecontrol (RRC) message (for example, RRC connection reconfigurationmessage).

Table 11 exemplifies the SchedulingRequestConfig information element.

TABLE 11 -- ASN1START SchedulingRequestConfig ::= CHOICE {  release NULL,  setup  SEQUENCE {   sr-PUCCH-ResourceIndex    INTEGER (0..2047),  sr-ConfigIndex   INTEGER (0..157),   dsr-TransMax   ENUMERATED {   n4, n8, n16, n32, n64, spare3, spare2, spare 1}  } }SchedulingRequestConfig-v1020 ::=  SEQUENCE { sr-PUCCH-ResourceIndexP1-r10   INTEGER (0..2047) OPTIONAL } -- ASN1STOP

Table 12 represents a field that is included in theSchedulingRequestConfig information element.

TABLE 12 SchedulingRequestConfig field descriptions dsr-TransMaxParameter for SR transmission. Value n4 represents 4 transmissions,value n8 represents 8 transmissions, and the rest is the same as above.sr-ConfigIndex Parameter(I_(SR)). Value 156 and 157 are not applied torelease 8. sr-PUCCH-ResourceIndex, sr-PUCCH-ResourceIndexP1Parameter(n_(PUCCH, SIR) ^((n, p)) for the respective antenna port P0and P1. E- UTRAN is configured the sr-PUCCH-ResourceIndexP1 only whensr- PUCCHResourceIndex is set.

Referring to Table 12, the UE receives sr-PUCCH-ResourceIndex parameterand sr-ConfigIndex parameter (I_(SR)) indicating the SR configurationindex through the RRC message for the SR transmission. By thesr-ConfigIndex parameter, SR_(PERIODICITY) indicating the periodicitywhen the SR is transmitted and N_(OFFSET,SR) indicating the subframewhere the SR is transmitted may be configured. That is, the SR istransmitted from a specific subframe that is periodically repeatedaccording to I_(SR) that is given by a higher layer. Also, the subframeresource and CDM/frequency division multiplexing (FDM) resource may beallocated to the resource for the SR.

Table 13 represents the SR transmission periodicity according to the SRconfiguring index and the SR subframe offset.

TABLE 13 SR configuration SR periodicity SR subframe Index (ms) offsetI_(SR) SR_(PERIODICITY) N_(OFFSET, SR) 0-4 5 I_(SR)  5-14 10 I_(SR) − 515-34 20 I_(SR) − 15 35-74 40 I_(SR) − 35  75-154 80 I_(SR) − 75 155-1562 I_(SR) − 155 157 1 I_(SR) − 157

Buffer Status Reporting (BSR)

FIG. 13 illustrates the MAC PDU used in the MAC entity in the wirelesscommunication system to which the present invention can be applied.

Referring to FIG. 13, the MAC PDU includes a MAC header, at least oneMAC service data unit (SDU) and at least one control element,additionally may include a padding. In some cases, at least one of theMAC SDUs and the MAC control elements may not be included in the MACPDU.

As an example of FIG. 13, it is common that the MAC control elements arelocated ahead of the MAC SDUs. And the size of MAC control elements maybe fixed or changeable. In case that the size of MAC control elements ischangeable, it may be determined through an extended bit whether thesize of MAC control elements is extended. The size of MAC SDU may bealso variable.

The MAC header may include at least one sub-header. In this time, atleast one sub-header that is included in the MAC header is respectivelycorresponding to the MAC SDUs, the MAC control elements and the padding,and the order of the sub-header is same as the arrangement order of thecorresponding elements. For example, as an example of FIG. 13, if thereare included MAC control element 1, MAC control element 2, a pluralityof MAC SDUs and padding in the MAC PDU, in the MAC header, the followingmay be arranged in order as a sub-header corresponding to the MACcontrol element 1, a sub-header corresponding to the MAC control element2, a plurality of sub-headers corresponding to a plurality of MAC SDUsrespectively and a sub-header corresponding to the padding.

Sub-headers included in the MAC header, as an example of FIG. 13, sixheader fields may be included. Particularly, the sub-header may includesix header fields of R/R/E/LCID/F/L.

For the sub-header corresponding to the very last one among thesub-header corresponding to the MAC control element of fixed size anddata fields included in the MAC PDU, as an example illustrated in FIG.13, the sub-header that is included four header fields may be used. Incase that the sub-header includes four fields like this, the four fieldsmay be R/R/E/LCID.

FIG. 14 and FIG. 15 illustrate the sub-header of the MAC PDU in thewireless communication system to which the present invention can beapplied.

Each field is described as below with reference to FIG. 14 and FIG. 15.

1) R: Reserved bit, which is not used.

2) E: Extended field, which represents whether the elementscorresponding to the sub-header are extended. For example, in case thatE field is ‘0’, the element corresponding to the sub-header isterminated without any repeat, and in case that E field is ‘1’, theelement corresponding to the sub-header is repeated once more and may beextended by twice in the length.

LCID: Logical channel identification field identifies a logical channelcorresponding to the relevant MAC SDU or identifies a type of therelevant MAC control element and padding. If the MAC SDU is associatedwith the sub-header, it may show which logical channel the MAC SDU iscorresponding to, and if the MAC control element is associated with thesub-header, it may show what the MAC control element is.

Table 14 represents the value of LCID for the DL-SCH

TABLE 14 Index LCID values 00000 CCCH 00001-01010 Identity of thelogical channel 01011-11001 Reserved 11010 Long DRX Command 11011Activation/Deactivation 11100 UE Contention Resolution Identity 11101Timing Advance Command 11110 DRX Command 11111 Padding

Table 15 represents the value of LCID for the UL-SCH

TABLE 15 Index LCID values 00000 CCCH 00001-01010 Identity of thelogical channel 01011-11000 Reserved 11001 Extended Power HeadroomReport 11010 Power Headroom Report 11011 C-RNTI 11100 Truncated BSR11101 Short BSR 11110 Long BSR 11111 Padding

In LTE/LTE-A system, the UE may report the buffer state of its own tothe network by configuring one of the index value among truncated BSR,short BSR, and long BSR in the LCID field.

The relationship of mapping between the index and the LCID valueillustrated in Table 14 and Table 15 is exemplified for the convenienceof the descriptions, but the present invention is not limited thereto.

4) F: Format field, which represents the size of L field.

5) L: Length field, which represents the size of MAC SDU and MAC controlelement corresponding to the sub-header. If the size of MAC SDU or MACcontrol element corresponding to the sub-header is equal to or less than127 bits, the 7-bit L field is used (FIG. 14(a)), otherwise, the 15-bitL field may be used (FIG. 14(b)). In case that the size of MAC controlelement is changeable, the size of MAC control element may be defined bythe L field. In case that the size of MAC control element is fixed, thesize of MAC control element may be determined without the size of MACcontrol element being defined by the L field, accordingly the F and Lfield may be omitted as shown in FIG. 15.

FIG. 16 illustrates formats of the MAC control elements in order toreport the buffer state in the wireless communication system to whichthe present invention can be applied.

In case of the truncated BSR and short BSR being defined in the LCIDfield of sub-header, the MAC control element corresponding to thesub-header, as shown in FIG. 16(a), may be configured to include onelogical channel group identification (LCG ID) field and one buffer sizefield indicating the buffer state of the LCG. The LCG ID field is foridentifying the logical channel group that is required to report thebuffer state, which may have the size of 2 bits.

The buffer size field is used for identifying the total amount ofavailable data from the all logical channels that are included in theLCG. The available data includes all the data that are going to betransmitted from the RLC layer and the PDCP layer, and the amount ofdata is represented in byte. In this time, the size of RLC header andMAC header may be excluded when calculating the amount of data. Thebuffer size field may be 6 bits.

In case of the extended BSR being defined in the LCID field ofsub-header, the MAC control element corresponding to the sub-header, asshown in FIG. 16(b), may include four buffer size fields indicating thebuffer state of four groups having 0 to 3 LCG IDs. Each of the buffersize fields may be used for identifying the total amount of availabledata from different logical channel groups.

Carrier Aggregation

A communication environment considered in the embodiments of the presentinvention includes all multi-carrier environments. That is, amulti-carrier system or a carrier aggregation (CA) system used in thepresent invention refers to a system for aggregating and utilizing oneor more component carriers having a bandwidth smaller than a targetbandwidth, for wideband support.

In the present invention, multi-carrier refers to carrier aggregation.Carrier aggregation includes aggregation of contiguous carriers andaggregation of non-contiguous carriers. In addition, the number ofcomponent carriers aggregated in downlink and uplink may be differentlyset. The case where the number and/or bandwidth of downlink componentcarriers (DL CCs) and the number and bandwidth of uplink componentcarriers (UL CCs) are the same is referred to as symmetric aggregationand the case where the number and/or bandwidth of downlink componentcarriers (DL CCs) and the number and bandwidth of uplink componentcarriers (UL CCs) are different is asymmetric aggregation. Such carrieraggregation is used interchangeable with the terms “carrieraggregation”, “bandwidth aggregation” or “spectrum aggregation”.

Carrier aggregation configured by aggregating two or more CCs aims atsupport a bandwidth of up to 100 MHz in an LTE-A system. When one ormore carriers having a bandwidth smaller than a target bandwidth areaggregated, the bandwidth of the aggregated carriers may be restrictedto a bandwidth used in the existing system, for backward compatibilitywith the existing IMT system. For example, the existing 3GPP LTE systemmay support bandwidths of 1.4, 3, 5, 10, 15 and 20 MHz and anLTE_Advanced (LTE_A) system evolved from the LTE system may support abandwidth greater than 20 MHz using only the bandwidths supported by theLTE system. Alternatively, the carrier aggregation system used in thepresent invention may define a new bandwidth so as to support CA,regardless of the bandwidths used in the existing system.

The above-described carrier aggregation environment may be called amultiple-cell environment. The cell is defined as a combination ofdownlink resources (DL CCs) and uplink resources (UL CCs), and theuplink resources are not mandatory. Accordingly, the cell may becomposed of downlink resources alone or both downlink resources anduplink resources. If a specific UE has one configured serving cell, theUE may have one DL CC and one UL CC. If a specific UE has two or moreconfigured serving cells, the UE may have DL CCs corresponding in numberto the number of cells and the number of UL CCs may be equal to or lessthan the number of DL CCs, and vice versa. If a specific UE has aplurality of configured service cells, a carrier aggregation environmentin which the number of DL CCs is greater than the number of UL CCs mayalso be supported. That is, carrier aggregation may be regarded asaggregation of two or more cells having different carrier frequencies(center frequencies of a cell). If carrier aggregation is supported,linkage between a carrier frequency (or a DL CC) of downlink resourcesand a carrier frequency (or a UL CC) of uplink resources may beindicated by system information. The DL CC and the UL CC may be referredto as DL cell and UL cell, respectively. The cell described hereinshould be distinguished from a “cell” as a general region covered by aBS.

A cell used in the LTE-A system includes a primary cell (PCell) and asecondary cell (SCell). The PCell and the SCell may be used as servicecells. In case of a UE which is in an RRC_connected state but does notset carrier aggregation or supports carrier aggregation, only oneserving cell composed of a PCell exists. In contrast, in case of a UEwhich is in an RRC_CONNECTED state and sets carrier aggregation, one ormore serving cells exist. The serving cell includes a PCell and one ormore SCell.

A serving cell (PCell and SCell) may be set through an RRC parameter.PhyCellId is a physical layer identifier of a cell and has an integervalue from 0 to 503. SCellIndex is a short identifier used to identifyan SCell and has an integer value from 1 to 7. A value of 0 is appliedto the PCell and SCellIndex is previously given to be applied to theScell. That is, a cell having a smallest cell ID (or a cell index) inServCellIndex becomes the PCell.

The PCell refers to a cell operating on a primary frequency (e.g., aprimary CC (PCC)). The PCell is used to perform an initial connectionestablishment process or a connection re-establishment process at a UE.The PCell may indicate a cell indicated in a handover process. The PCellrefers to a cell for performing control-associated communication amongserving cells set in a carrier aggregation environment. That is, a UEmay receive a PUCCH allocated by a PCell to which the UE belongs andperform transmission and use only the PCell to acquire systeminformation and change a monitoring procedure. In evolved universalterrestrial radio access (E-UTRAN), a UE supporting a carrieraggregation environment may change only the PCell for a handoverprocedure using an RRCConnectionReconfiguration message of a higherlayer including mobilityControlInfo.

The SCell refers to a cell operating on a secondary frequency (e.g., asecondary CC (SCC)). Only one PCell may be allocated to a specific UEand one or more SCells may be allocated to the specific UE. The SCellmay be configured after radio resource control (RRC) connectionestablishment and may be used to provide additional radio resources. APUCCH is not present in cells except for the PCell among serving cellsset in a carrier aggregation environment, that is, the SCells. E-UTRANmay provide all system information associated with the operation of anassociated cell in an RRC_CONNECTED state via a dedicated signal whenSCells are added to a UE supporting a carrier aggregation environment.Change of system information may be controlled by release and additionof the SCell. At this time, an RRCConnectionReconfiguration message of ahigher layer may be used. The E-UTRAN may transmit a dedicated signalhaving a different parameter to each UE, rather than broadcasting asignal in the associated SCell.

After an initial security activation process begins, an E-UTRAN mayconfigure a network by adding one or more SCells to a PCell initiallyconfigured in a connection establishment process. In a carrieraggregation environment, the PCell and the SCell may operate asrespective CCs. In the following embodiments, a primary CC (PCC) may beused as the same meaning as the PCell and a secondary CC (SCC) may beused as the meaning as the SCell.

FIG. 17 represents an example of component carrier and carrieraggregation in the wireless communication system to which the presentinvention can be applied.

FIG. 17(a) represents a single carrier structure that is used in a LTEsystem. There are DL CC and UL CC in component carrier. One componentcarrier may have 20 MHz frequency range.

FIG. 17(b) represents a carrier aggregation structure that is used in aLTE-A system. FIG. 17(b) represents a case that three component carriershaving 20 MHz frequency are aggregated. There are three DL CCs and ULCCs respectively, but the number of DL CCs and UL CCs are not limitedthereto. In case of the carrier aggregation, the UE enables to monitorthree CCs at the same time, to receive the DL signal/data, and totransmit the UL signal/data.

If, N DL CCs are managed in a specific cell, the network may allocate M(M≤N) DL CCs. In this case, the UE may monitor the limited M DL CCs onlyand receive the DL signal. Also, the network may give a priority to L(L≤M≤N) DL CCs and have the prioritized DL CCs allocated to the UE, inthis case, the UE should monitor the DL CCs without fail. This way maybe applied for the UL transmission.

The linkage between the DL resource carrier frequency (or DL CC) and theUL resource carrier frequency (or UL CC) may be instructed by a higherlayer message like RRC message or system information. For example, thecombination of DL resource and UL resource may be configured by thelinkage that is defined by system information block type 2 (SIB2).Particularly, the linkage may signify the mapping relationship betweenthe DL CC through which the PDCCH carrying a UL grant is transmitted andthe UL CC that uses the UL grant, or signify the mapping relationshipbetween the DL CC (or UL CC) through which the data for HARQ istransmitted and the UL CC (or DL CC) through which the HARQ ACK/NACKsignal is transmitted.

Uplink Resource Allocation Procedure

In 3GPP LTE/LTE-A system, in order to maximize resource utilization, thedata transmission and reception method based on scheduling of an eNB isused. This signifies that if there are data to transmit by a UE, the ULresource allocation is preferentially requested to the eNB, and the datamay be transmitted using only UL resources allocated by the eNB.

FIG. 18 illustrates a UL resource allocation procedure of a UE in thewireless communication system to which the present application can beapplied.

For effective utilization of the UL radio resources, an eNB should knowwhich sorts and what amount of data to be transmitted to the UL for eachUE. Accordingly, the UE itself may forward the information of UL data totransmit, and the eNB may allocate the UL resources to the correspondingUE based on this. In this case, the information of the UL data that theUE forwards to the eNB is the quality of UL data stored in its buffer,and this is referred to as a buffer status report (BSR). The BSR istransmitted using a MAC control element in case that the resources onthe PUSCH in current TTI are allocated to the UE and the reporting eventis triggered.

FIG. 18(a) exemplifies a UL resource allocation procedure for actualdata in case that the UL radio resources for the buffer status reporting(BSR) are not allocated to a UE. That is, for a UE that switches a stateof active mode in the DRX mode, since there is no data resourceallocated beforehand, the resource for UL data should be requestedstarting from the SR transmission through the PUCCH, in this case, theUL resource allocation procedure of 5 steps is used.

Referring to FIG. 18(a), the case that the PUSCH resource fortransmitting the BSR is not allocated to a UE is illustrated, and the UEtransmits the scheduling request (SR) to an eNB first in order to beallocated with the PUSCH resources (step, S1801).

The scheduling request (SR) is used to request in order for the UE to beallocated with the PUSCH resource for UL transmission in case that thereporting event is occurred but the radio resource is not scheduled onthe PUSCH in current TTI. That is, the UE transmits the SR on the PUCCHwhen the regular BSR is triggered but does not have the UL radioresource for transmitting the BSR to the eNB. The UE transmits the SRthrough the PUCCH or starts the random access procedure according towhether the PUCCH resources for the SR are configured. In particular,the PUCCH resources in which the SR can be transmitted may be determinedas a combination of the PRB through which the SR is transmitted, thecyclic shift (CS) applied to a basic sequence (e.g., ZC sequence) forspread in frequency domain of the SR and an orthogonal code (OC) forspread in time domain of the SR. Additionally, the SR periodicity andthe SR subframe offset information may be included. The PUCCH resourcesthrough which the SR can be transmitted may be configured by a higherlayer (e.g., the RRC layer) in UE-specific manner

When a UE receives the UL grant for the PUSCH resources for BSRtransmission from an eNB (step, S1803), the UE transmits the triggeredBSR through the PUSCH resources which are allocated by the UL grant(step, S1805).

The eNB verifies the quality of data that the UE actually transmit tothe UL through the BSR, and transmits the UL grant for the PUSCHresources for actual data transmission to the UE (step, S1807). The UEthat receives the UL grant for actual data transmission transmits theactual UL data to the eNB through the PUSCH resources (step, S1809).

FIG. 18(b) exemplifies the UL resource allocation procedure for actualdata in case that the UL radio resources for the BSR are allocated to aUE.

Referring to FIG. 18(b), the case that the PUSCH resources for BRStransmission are already allocated to a UE is illustrated. In the case,the UE transmits the BSR through the allocated PUSCH resources, andtransmits a scheduling request to an eNB (step, S1811). Subsequently,the eNB verifies the quality of data to be transmitted to the UL by theUE through the BSR, and transmits the UL grant for the PUSCH resourcesfor actual data transmission to the UE (step, S1813). The UE thatreceives the UL grant for actual data transmission transmits the actualUL data to the eNB through the allocated PUSCH resources (step, S1815).

FIG. 19 is a diagram for describing a latency in C-plane required in3GPP LTE-A to which the present invention can be applied.

Referring to FIG. 19, 3GPP LTE-A requests a transition time from an idlemode (a state that IP address is allocated) to a connected mode to beless than 50 ms. In this time, the transition time includes aconfiguration time (except latency for transmitting S1) in a user plane(U-plane). In addition, a transition time from a dormant state to anactive state in the connection mode is requested to be less than 10 ms.

The transition from the dormant state to the active state may occur in 4scenarios as follows.

-   -   Uplink initiated transition, synchronized    -   Uplink initiated transition, unsynchronized    -   Downlink initiated transition, synchronized    -   Downlink initiated transition, unsynchronized

FIG. 20 is a diagram for describing a transition time from the dormantstate to the active state for a synchronized UE required in 3GPP LTE-Ato which the present invention can be applied.

In FIG. 20, the UL resource allocation procedure of 3 steps (in case ofUL radio resources for the BSR are allocated) described in FIG. 18 aboveis illustrated. In LTE-A system, the latency is required for UL resourceallocation as represented in Table 11 below.

Table 16 represents a transition time from the dormant state to theactive state initiated by a UL transmission, in case of a synchronizedUE which is required in LTE-A system.

TABLE 16 Component Description Time [ms] 1 Average delay to next SRopportunity 0.5/2.5 (1 ms/5 ms PUCCH cycle) 2 UE sends SchedulingRequest 1 3 eNB decodes Scheduling Request and 3 generates theScheduling Grant 4 Transmission of Scheduling Grant 1 5 UE ProcessingDelay (decoding of 3 scheduling grant + L1 encoding of UL data) 6Transmission of UL data 1 Total delay  9.5/11.5

Referring to FIG. 20 and Table 16, as an average delay due to a RACHscheduling section that has a RACH cycle of 1 ms/5 ms, 0.5 ms/2.5 ms isrequired, and 1 ms is required for a UE to transmit the SR. And 3 ms isrequired for an eNB to decode the SR and generate the scheduling grant,and 1 ms is required to transmit the scheduling grant. And 3 ms isrequired for a UE to decode the scheduling grant and encode the UL datain L2 layer, and 1 ms is required to transmit the UL data.

As such, total 9.5/15.5 ms are required for a UE to complete a procedureof transmitting the UL data.

Accordingly, due to system characteristics of transmitting data based onscheduling by an eNB, the problem of increasing the latency even in caseof transmitting UL data of a UE.

Particularly, in case of an intermittent application (e.g., a healthcare, a traffic safety, etc.) or an application in which fasttransmission is required, such a data transmission method is not propersince it causes the latency inevitably.

Method for Requesting Scheduling Using a Multiple Scheduling RequestConfiguration

In order to perform a HARQ operation in a receiving end, it is requiredto store data that are still not successfully decoded yet, and thestorage for this is referred to as a soft buffer. That is, the softbuffer signifies a space in which the soft value is stored in thereceiving end before performing a channel decoding for the datatransmitted from a transmission end. The soft buffer is controlled foreach transmission block (TB) (or a HARQ process).

In LTE/LTE-A system, in case of DL, a memory size of the soft bufferwithin a UE is determined according to a UE category. The UE reports itscategory information and the like to a network, and determines a size ofthe soft buffer for each transmission block by considering a UEcapacity.

When transmitting DL data, an eNB does not notify a size of DL data tothe UE. Instead, the eNB notifies only the information such as rankinformation, number of stream, etc. For example, when the eNB transmitsthe DL data with four streams the UE logically divides the soft bufferinto identical four sections, and stores them in the soft buffer foreach stream.

On the other hand, in case of UL, an eNB configures the memory of softbuffer using the BSR information received from a UE. That is, the eNB isrequired to know the BSR information in order to configure a size of thesoft buffer.

FIG. 21 is a diagram for describing the soft buffer in the wirelesscommunication system to which the present invention can be applied.

LTE/LTE-A physical layers are interfaced using the MAC layer and thetransport channel which are higher layers. In order to detect errorwithin the transport block which is encoded in the receiving end, acyclic redundancy check is attached to the transport block transmittedfrom the MAC layer, and the transport block is divided by a code blockin order to be fit to a code block size defined in a turbo code.

An additional CRC is attached to each code block, and the code block isinputted in a turbo encoder and to which a turbo encoding whose codingrate is ⅓ is applied. The code block is outputted from the turbo encoderas systematic bits, first parity bits and second parity bits.

Each of the systematic bits, the first parity bits and the second paritybits are interleaved through a subblock interleaver. The interleavedbits are stored in a virtual circular buffer.

FIG. 21(a) illustrates a code block stored in the virtual circularbuffer.

In FIG. 21, v_(k) ⁽⁰⁾ (k=0, . . . , K_(Π)−1) represents interleavedsystematic bits sequence, each of v_(k) ⁽¹⁾ (k=0, . . . , K_(Π)−1) andv_(k) ⁽²⁾ (k=0, . . . , K_(Π)−1) represent interleaved parity bitsequences.

As shown in FIG. 21(a), the systematic bits are firstly stored in thevirtual cyclic buffer, and the first parity bits and the second paritybits are alternately stored by one by one bit. The length of virtualcyclic buffer equals to K_(w)=3K_(Π).

Since a receiving side (i.e., an eNB that receives UL or a UE thatreceives DL) is required to store the data not successfully decoded yetin order to perform the HARQ process, for this, the receiving sideshould setup a soft buffer.

In case of the DL-SCH and the PCH transmission channel, a size N_(cb) ofthe soft buffer for each code block is determined as Equation 6 below.

$\begin{matrix}{N_{cb} = {\min\left( {\left\lfloor \frac{N_{IR}}{C} \right\rfloor,K_{w}} \right)}} & \left\lbrack {{Equation}\mspace{14mu} 6} \right\rbrack\end{matrix}$

In Equation 6, C represents the number of code blocks. N_(IR) representsthe size of soft buffer for transmission block.

The soft buffer size N_(IR) for transmission block is defined asEquation 7 below.

$\begin{matrix}{N_{IR} = \left\lfloor \frac{N_{soft}}{K_{C} \cdot K_{MIMO} \cdot {\min\left( {M_{DL\_ HARQ},M_{limit}} \right)}} \right\rfloor} & \left\lbrack {{Equation}\mspace{14mu} 7} \right\rbrack\end{matrix}$

In Equation 7, floor(x) is a function that represents the biggestinteger among integers that are the same or smaller than x, and min(x,y) is a function that represents a smaller value between x and y.N_(soft) is a total number of soft channel bits. N_(soft) is determinedaccording to UE category. K_(MIMO) is a value determined according touse of spatial multiplex. M_(limit) is a constant value, and is 8.

On the other hand, in case of the UL-SCH and the MCH transmissionchannel, a size N_(cb) of soft buffer for each code block is determinedas Equation 8 below.N_(cb)=K_(w)   [Equation 8]

In case of UL of Equation 8, an eNB configures the soft buffer in threefold size of UL data based on the BSR for each UE. For example, whentransmitting the BSR reporting that the data to be transmitted by the UEis 10000, the eNB configures the soft buffer size in a size of 30000(=3*10000).

As such, in the eNB, the soft buffer is always configured as three foldsize of UL data for each UE, and this is because a mother coding rate(turbo encoding and decoding) is ⅓.

FIG. 21(b) is a diagram for describing a soft combining in the softbuffer.

In UL/DL data transmission and reception, errors may occur in the datatransmitted according to channel environment, etc. As a way of errorcorrection, the ARQ method or more improved form of HARQ method may beused. According to the HARQ method, in case that the data received in areception end are not properly decoded, NACK is feedback to transmissionend.

The reception end (i.e., an eNB or a UE) stores previously received data(i.e., data not properly decoded) in a soft buffer during apredetermined time, and soft combines the data retransmitted from thetransmission end with the data of the same transmission block stored inthe soft buffer and decode it. If there is no data to soft combine, thereception end performs decoding with the received data only.

In 3GPP LTE/LTE-A, the HARQ of incremental redundancy (IR) type is used,and a redundancy version (RV) is changed for every retransmission. Aninitial position within a buffer for retransmission is defined by RVvalues (rv_(idx)=0, 1, 2 or 3).

As described above, in case of UL, an eNB configures a size of softbuffer (i.e., three fold of UL data reported in the BSR) based on theBSR information received from a UE.

Table 17 illustrates buffer size labels for the BSR.

TABLE 17 Index Buffer Size (BS) value [bytes] 0 BS = 0 1  0 < BS <= 10 210 < BS <= 12 3 12 < BS <= 14 4 14 < BS <= 17 5 17 < BS <= 19 6 19 < BS<= 22 7 22 < BS <= 26 8 26 < BS <= 31 9 31 < BS <= 36 10 36 < BS <= 4211 42 < BS <= 49 12 49 < BS <= 57 13 57 < BS <= 67 14 67 < BS <= 78 1578 < BS <= 91 16  91 < BS <= 107 17 107 < BS <= 125 18 125 < BS <= 14619 146 < BS <= 171 20 171 < BS <= 200 21 200 < BS <= 234 22 234 < BS <=274 23 274 < BS <= 321 24 321 < BS <= 376 25 376 < BS <= 440 26 440 < BS<= 515 27 515 < BS <= 603 28 603 < BS <= 706 29 706 < BS <= 826 30 826 <BS <= 967 31  967 < BS <= 1132 32 1132 < BS <= 1326 33 1326 < BS <= 155234 1552 < BS <= 1817 35 1817 < BS <= 2127 36 2127 < BS <= 2490 37 2490 <BS <= 2915 38 2915 < BS <= 3413 39 3413 < BS <= 3995 40 3995 < BS <=4677 41 4677 < BS <= 5476 42 5476 < BS <= 6411 43 6411 < BS <= 7505 447505 < BS <= 8787 45  8787 < BS <= 10287 46 10287 < BS <= 12043 47 12043< BS <= 14099 48 14099 < BS <= 16507 49 16507 < BS <= 19325 50 19325 <BS <= 22624 51 22624 < BS <= 26487 52 26487 < BS <= 31009 53 31009 < BS<= 36304 54 36304 < BS <= 42502 55 42502 < BS <= 49759 56 49759 < BS <=58255 57 58255 < BS <= 68201 58 68201 < BS <= 79846 59 79846 < BS <=93479 60  93479 < BS <= 109439 61 109439 < BS <= 128125 62 128125 < BS<= 150000 63    BS > 150000

Referring to Table 17, a UE divides the UL data size by 64 levels, andtransmits the information of the UL data size to an eNB using the BSR of6 bits. For example, in case that the UL data size to be transmitted is350 byte, the UE transmits index value 24 to the eNB using the BSR of 6bits.

If the eNB does not know the B SR information, the eNB should configurethe soft buffer size by assuming that the UL data size is the biggestdata size. As such, in case of configuring the soft buffer size underthe assumption of the biggest data size, there is a drawback of inducinga memory waste of the eNB.

Similarly, if the eNB configures a soft buffer with an arbitrarydetermination of the data size, consequently, a case may occur that thedata is not written in the soft buffer (i.e., a case that the UL data isgreater than the soft buffer size) since the eNB does not know whichsize of data is transmitted from a UE. Therefore, if the eNB arbitrarilyconfigures the soft buffer as such, the channel decoding is available inthe eNB, but there is a drawback that a data loss occurs in the UL data.

As such, according to the conventional method, in order for the UE totransmit the UL data to the eNB, it is required to transmit the BSR tothe eNB, and the UE always follows 5-step the UL data transmissionmethod (or the 3-step UL data transmission method in case that the ULresource is pre-allocated to the BSR; refer to FIG. 18) regardless ofwhich application generates the UL data or the data size.

That is, the UE transmits the information of the UL data that is goingto be sent by the UE itself to the eNB through the BSR, and the eNBallocates the UL resource to the corresponding UE based on the BSRinformation.

However, in case of performing the general 5-step UL resource allocationprocedure (or the UL data transmission procedure), it is unavoidable ofthe latency to occur according to the UL data transmission.Particularly, in order to transmit the UL data that is intermittentlygenerated within a predetermined size (in particular, small size) or theUL data that is generated by an application which is sensitive to delay,it is preferable to decrease the latency.

Accordingly, an embodiment of the present invention proposes a methodfor requesting scheduling using SRs classified into a plurality oftypes.

In accordance with an embodiment of the present invention, BSRinformation may be replaced with a multiple SR configuration (or amultiple SR type). That is, UE sends an SR to an eNB through differentSR resources according to SR types. Furthermore, the eNB determines theSR types based on the received SR resources and allocates (assigns)uplink resources to corresponding UE based on the SR types.

In an embodiment of the present invention, in order to reduce delaygenerated when UL data that is intermittently generated and has a smallsize is transmitted, a data range, that is, the subject of a multiple SRconfiguration, may be configured to be only a specific range or therange of a specific size of data in the entire buffer size level.Furthermore, a data region matched with each SR type for each certainrange within a set specific range can be determined.

For example, in the example of Table 17, only the index 0 to the index11 in a buffer size level set as the entire 64 region may be set as theregion of data, that is, the subject of a multiple SR configuration.Furthermore, three regions, for example, the index 0 to the index 3, theindex 4 to the index 7, and the index 8 to the index 11 may be divided.Different SR types may be matched to the respective three regions andconfigured.

Furthermore, if the size of data is 10 bytes or less (i.e., the size ofdata≤10), it may be configured as an SR type 1. If the size of data ismore than 10 bytes to 50 bytes or less (i.e., 10<the size of data≤50),it may be configured as an SR type 2. If the size of data is more than50 bytes to less than 100 bytes (i.e., 50<the size of data≤100), it maybe configured as an SR type 3.

Furthermore, the region of data, that is, the subject of a multiple SRconfiguration, may correspond to an existing entire buffer size level.

For example, as in the example of Table 17, the buffer size level set asthe entire 64 region may be divided into a total of 8 regions for each 8BSR index, and different SR types may be matched with the respective 8regions and configured.

Such a configuration of the multiple SR types may be set in aUE-specific way or cell-specific way. That is, the range of the entiredata region, that is, the subject of a multiple SR configuration, therange of each region (i.e., the range of data) divided within the entiredata region, that is, the subject of the multiple SR configuration, andthe number of regions may be determined in a cell-specific way or in aUE-specific way. Furthermore, the configuration of the multiple SR typesmay be dynamically changed or may be semi-statically changed.

For example, if multiple SR types are configured in a UE-specific way,multiple SR types respectively mapped to 4 regions, that is, the indices0 to 3, the indices 4 to 7, indices 8 to 11, and the indices 12 to 15,may be configured in UE 1. Multiple SR types respectively mapped to 3regions, that is, the indices 0 to 4, the indices 5 to 9, and theindices 10 to 14, may be configured in UE 2.

Furthermore, in the UE 1, if the size of data is 10 bytes or less (i.e.,the size of data≤10), it may be configured as an SR type 1. If the sizeof data is more than 10 bytes to 50 bytes or less (i.e., 10<the size ofdata≤50), it may be configured as an SR type 2. If the size of data ismore than 50 bytes to 100 bytes or less (i.e., 50<the size of data≤100),it may be configured as an SR type 3. In the UE 2, if the size of datais 30 bytes or less, (i.e., the size of data≤30), it may be configuredas an SR type 1. If the size of data is more than 30 bytes to 90 bytesor less (i.e., 30<the size of data≤90), it may be configured as an SRtype 2.

In this case, the range of the aforementioned value (or index) is onlyfor convenience of description, and the present invention is not limitedthereto. That is, the range of the entire data in which multiple SRtypes are configured (or the range of BSR indices), the number ofregions divided within the range of corresponding data (i.e., the numberof multiple SR types), and the range of data mapped to each SR type (orthe range of a BSR index) may be set in various ways.

If the multiple SR types are configured as described above, UE mayselectively use the SR types based on the size of UL data to betransmitted. That is, the UE may request resource allocation(assignment) for the UL data from an eNB using the type of UL data to betransmitted or an SR type mapped to the size of the UL data.

A method for sending multiple SR type configuration information isdescribed below.

First, new information elements may be newly defined as the multiple SRconfiguration information.

That is, information for configuring the multiple SR types may bedefined through a multiple SR configuration by omitting informationabout the transmission of a BSR for each UE or for each logical channelID of UE and additionally using the size of UL data corresponding to aspecific BSR.

Furthermore, in current LTE/LTE-A, UE transmits (sends) BSR informationhaving a length of 6 bits to an eNB through a single SR configurationusing RRC. As described above, an embodiment of the present inventionmay include a scheduling request procedure for sending BSR informationof 6 bits in length within the multiple SR configuration.

Table 18 illustrates information elements for configuring the multipleSR types.

TABLE 18 -- ASN1START SchedulingRequestConfig ::= CHOICE {  releaseNULL,  setup SEQUENCE {   sr0-PUCCH-ResourceIndex    INTEGER (0..2047),  sr0-ConfigIndex    INTEGER (0..157),   dsr0-TransMax   ENUMERATED {n4,n8, n16, n32, n64, ...}   sr1-PUCCH-ResourceIndex    INTEGER (0..2047),  sr1-ConfigIndex    INTEGER (0..157),   dsr1-TransMax   ENUMERATED {n4,n8, n16, n32, n64, ...}   sr2-PUCCH-ResourceIndex    INTEGER (0..2047),  sr2-ConfigIndex    INTEGER (0..157),   dsr2-TransMax   ENUMERATED {n4,n8, n16, n32, n64, ...}   ...  } } SchedulingRequestConfig-v1020 ::= SEQUENCE {  sr-PUCCH-ResourceIndexP1-r10   INTEGER(0..2047)     OPTIONAL } -- ASN1STOP

Referring to Table 18, a “dsr-TransMax” field, an “sr-ConfigIndex”field, and an “sr-PUCCH-ResourceIndex” (and/or“sr-PUCCH-ResourceIndexP1”) field may be defined according to respectiveSR types, such as an SR type 0, an SR type 1, and an SR type 2, . . . .In this case, the SR type 0 may correspond to an existing SRconfiguration for sending a BSR of 6 bits (i.e., an UL assignmentrequest for sending a BSR).

The “dsr-TransMax” field is a parameter indicative of a maximum numberof transmissions of an SR. An n4 value indicates four transmissions, ann8 value indicates eight transmissions, and the rest is the same.

The “sr-ConfigIndex” field indicates the value of an SR configurationindex I_(SR) indicative of SR periodicity SR_(PERIODICITY) and an SRsubframe offset N_(OFFSET,SR) (refer to Table 13).

The “sr-PUCCH-ResourceIndex” and the “sr-PUCCH-ResourceIndexP1” fieldindicate the respective PUCCH resource indices n_(PUCCH,SRI) ^((1,p)) ofantenna ports P0 and P1.

As described above, the PUCCH resource index n_(PUCCH,SRI) ^((1,p)), theSR configuration index I_(SR), and the number of times that an SR istransmitted may be set for each SR type.

UE may receive information elements for configuring multiple SR typesfrom an eNB through an RRC message. For example, UE may receive theinformation elements from an eNB through an RRC connectionreconfiguration message or an RRC connection setup message.

SR resources correspond to the logical indices of the PUCCH formats1/1a/1b in a one-to-one way. That is, the SR resources are assigned asin Equation 9 below.n_(PUCCH) ^((1,{tilde over (p)}))=n_(PUCCH,SRI)^((1,{tilde over (p)}))  [Equation 9]

As a result, this means that the resource assignment of the PUCCHformats 1 is simply multiplexed according to the multiple SRconfiguration.

Accordingly, a method of requesting scheduling in accordance with anembodiment of the present invention means that a plurality of SRresources is assigned to UE for each SR type and the UE sends an SRthrough a plurality of PUCCH resources.

Although not illustrated in Table 18, the multiple SR configurationinformation may also include information about the size of UL dataaccording to each SR type (e.g., a maximum supportable size of data).For example, a maximum supportable size of data according to the SR type1 may indicate 100 bytes (i.e., the size of data≤100), and a maximumsupportable size of data according to the SR type 2 may indicate 200bytes (i.e., 100<the size of data≤200).

Furthermore, information about the size of UL data according to each SRtype may be previously set and known to both UE and an eNB.

SR resources according to SR types are described in detail below withreference to the drawings.

FIG. 22 is a diagram illustrating SR resources according to SR types inaccordance with an embodiment of the present invention.

As described above, in accordance with an embodiment of the presentinvention, a plurality of SR resources is assigned to UE for each SRtype through a multiple SR configuration.

In this case, an SR resource configured according to an SR type aredetermined by a combination of a PRB in which an SR is transmitted, aCyclic Shift (CS) applied to a base sequence (e.g., a ZC sequence) forthe spreading of an SR in a frequency domain, and Orthogonal Code (OC)for the spreading of the SR in a time domain.

In FIG. 22, it is assumed that in the same subframe index, an SRresource 2201 according to the SR type 1 and an SR resource 2203according to the SR type 2 are configured in the same PRB.

In this case, an eNB may identify the SR resource 2201 according to theSR type 1 and the SR resource 2203 according to the SR type 2 based on acombination of a CS and OC.

For example, a CS index 1 and an OC index 1 may be applied to the SRresource 2201 according to the SR type 1, whereas a CS index 2 and an OCindex 3 may be applied the SR resource 2203 according to the SR type 2.In this case, although the SR type 1 and the SR type 2 aresimultaneously transmitted in the same PRB, an eNB is able to detecteach SR by a combination of the CS and the OC.

If it is assumed that the SR resource 2201 according to the SR type 1and the SR resource 2203 according to the SR type 2 are configured indifferent PRBs in the same subframe index, the eNB may identify the SRtype 1 and the SR type 2 based on a PRB in which an SR is transmitted.

In addition, an SR resource configured for each SR type may bedetermined based on information about an SR periodicity and an SRsubframe offset.

In FIG. 22, it is assumed that the SR periodicity of the SR resource2201 according to the SR type 1 is set to 4 subframes and the SRperiodicity of the SR resource 2203 according to the SR type 2 is set to2 subframes. It is also assumed that the SR resource 2201 according tothe SR type 1 and the SR resource 2203 according to the SR type 2 havethe same subframe offset.

In other words, the SR resource 2201 according to the SR type 1 may beassigned to a subframe index 0, a subframe index 4, a subframe index 8,. . . . The SR resource 2203 according to the SR type 2 may be assignedto a subframe index 0, a subframe index 2, a subframe index 4, asubframe index 6, a subframe index 8, . . . .

In this case, if a subframe in which the SR resource 2201 according tothe SR type 1 is transmitted overlaps with a subframe in which the SRresource 2203 according to the SR type 2 is transmitted, the eNB mayattempt to detect both the SR type 1 and the SR type 2. In contrast, ifa subframe in which the SR resource 2201 according to the SR type 1 istransmitted does not overlap with a subframe in which the SR resource2203 according to the SR type 2 is transmitted, the eNB may attempt todetect any one of the SR type 1 and the SR type 2.

FIG. 23 is a diagram illustrating a method for requesting scheduling fortransmitting UL data in accordance with an embodiment of the presentinvention.

In FIG. 23, it is assumed that a plurality of SR types has beenconfigured as follows.

First, an SR type 1 (Type-1 SR) may be used when UE uses an SR procedurefor common uplink data transmission.

Furthermore, an SR type 2 (Type-2 SR) may be used when UE uses an SRprocedure for sending UL data that requires low latency, that is, ULdata having a predefined size of data L₁ (i.e., 100<the size ofdata≤1000).

Furthermore, an SR type 3 (Type-3 SR) may be used when UE uses an SRprocedure for sending UL data that requires low latency, that is, ULdata having a predefined size of data L₂ (i.e., 1000<the size ofdata≤10000).

Furthermore, an SR type 4 (Type-4 SR) may be used when UE uses an SRprocedure for sending UL data that requires low latency, that is, ULdata having a predefined size of data L₃ (i.e., 10000<the size ofdata≤20000).

A process of assigning uplink resources to the SR type 1, the SR type 2,and the SR type 3 is described below.

UE in which a multiple SR configuration has been configured sends ascheduling request to an eNB in order to be assigned PUSCH resources forsending UL data at step 2301, 2311, and 2317.

In this case, the UE sends an SR type, selected based on the type of ULdata to be transmitted on a PUCCH and/or the size of the UL data, to theeNB.

As described above, an SR type transmitted by the UE is determined basedon a resource in which an SR is transmitted. That is, the UE sends theSR to the eNB through an SR resource corresponding to the selected SRtype.

Such an SR resource (i.e., a multiple SR configuration) may be set by ahigh layer (e.g., an RRC layer) in a UE-specific way or a cell-specificway. Furthermore, the multiple SR configuration may be dynamically orsemi-statically changed.

In the example of FIG. 23, when the UE sends the SR through an SRresource corresponding to the SR type 1, the eNB may determine thereceived SR to be the SR type 1. Likewise, when the UE sends the SRthrough an SR resource corresponding to the SR type 2, the eNB maydetermine the received SR to be the SR type 2.

The eNB determines the SR type based on the SR resource received fromthe UE and performs a process of assigning uplink resources based on thedetermined SR type.

First, if the UE sends the SR type 1 to the eNB, the eNB may perform acommon 5-step UL resource assignment procedure by detecting energy(i.e., detecting on/off) in the resource of the SR type 1.

That is, as in the example of FIG. 18(a), the eNB sends an UL grant fora PUSCH resource for sending a BSR to the UE at step 2303.

The UE that has received the UL grant for the BSR from the eNB sends aBSR, triggered through the PUSCH resources assigned by the UL grant, tothe eNB at step 2305.

The eNB checks the amount of data to be actually transmitted in uplinkby the UE based on the BSR and sends an UL grant for a PUSCH resourcefor sending the actual data to the UE at step 2307. In this case, theeNB sets up a soft buffer size corresponding to the size of the actualdata to be transmitted in uplink by the UE based on the BSR.

The UE that has received the UL grant for sending the actual data fromthe eNB sends the actual UL data to the eNB through the assigned PUSCHresource at step 2309.

Thereafter, when the UE sends the SR type 2 to the eNB, the eNB mayperform a 3-step UL resource assignment procedure without a BSR request(i.e., without UL resource assignment for a BSR and without sending theBSR) by detecting energy (i.e., detecting on/off) in the resource of theSR type 2.

That is, the eNB sends an uplink grant (i.e., an UL grant) for a PUSCHresource for sending actual data to the UE at step 2313.

In this case, the PUSCH resource assigned to send the actual data may bedetermined based on information about the size of the data that has beenprovided from the UE to the eNB through the SR type 2 at step 2311, thesize of data L₁ (100<size of data≤1000). Furthermore, the eNB sets up asoft buffer size (e.g., 3000=1000*3) corresponding to the size of dataL₁.

The UE sends the actual data to the eNB through the PUSCH resourceassigned by the UL grant from the eNB at step 2315.

Thereafter, when the UE sends the SR type 3 to the eNB, the eNB mayperform a 3-step UL resource assignment procedure without a BSR request(i.e., without UL resource assignment for a BSR and without sending theBSR) by detecting energy (i.e., detecting on/off) in the resource of theSR type 3.

That is, the eNB sends an uplink grant (i.e., an UL grant) for the PUSCHresource for sending the actual data to the UE at step 2317.

In this case, the PUSCH resource assigned to send the actual data may bedetermined based on information about the size of the data that has beenprovided from the UE to the eNB through the SR type 3 at step 2317, thatis, the size of data L₂ (1000<the size of data≤10000). Furthermore, theeNB sets up a soft buffer size (e.g., 30000=3*10000) corresponding tothe size of data L₂.

The UE sends the actual data to the eNB through the PUSCH resourceassigned by the UL grant from the eNB at step 2321.

Processing in UE and an eNB for UL data transmission using a multiple SRconfiguration is described in detail below with reference to thedrawings.

FIG. 24 is a diagram illustrating a process of sending UL data using amultiple SR configuration in accordance with an embodiment of thepresent invention.

In FIG. 24, it is assumed that major applications that generate UL datainclude three cases as follows.

Case 1—data of a specific criterion or less size that isintermittently/aperiodically generated (e.g., health care and trafficsafety information)

Case 2—data of various sizes that is generatedintermittently/aperiodically

Case 3—data other than Case 1 and Case 2

In the case of Case 3, the common 5-step SR-based uplink resourceassignment process is performed.

Processing in UE and the eNB in “Case 1” and “Case 2” is describedbelow.

FIG. 24(a) illustrates an UL data transmission process in Case 1.

An embodiment of the present invention proposes a new scheduling requestmethod not including a BSR in order to send data of a small size thatmay be intermittently generated more rapidly as in “Case 1.”

In the case of data of a small size when an event is intermittentlygenerated as in “Case 1”, data may be transmitted through the proposed3-step SR procedure not including a BSR.

In this case, an eNB previously defines a maximum supportable size ofdata L₁ regardless of the type and size of data transmitted by UE anddefines a corresponding soft buffer size.

A maximum supportable size of data that may be used by each of pieces ofUE may be controlled through an RRC message. Furthermore, informationabout an SR resource corresponding to each SR type may also becontrolled through an RRC message.

Referring to FIG. 24(a), UE determines whether the size of datatransmitted in uplink is a specific length L₁ or less (or less than thespecific length L₁) supported in a multiple SR configuration at step2401.

The UE selects an SR type “j” according to the size of the data at step2403. That is, if the size of the data is L₁ or less (or less than), theUE selects the SR type 1. If not, the UE selects the SR type 0. Theopposite is also possible.

Furthermore, the UE sends the selected SR type 0 or 1 to the eNB througha PUCCH resource corresponding to a corresponding SR type at step 2405.

The eNB performs an UL grant generation and soft buffer configurationfor assigning the resources of UL data based on the size of dataobtained by detecting the SR of the UE at step 2407.

More specifically, the eNB obtains information about the size of thedata (i.e., L₁ or less) based on the received SR type, generates an ULgrant according to the size of the data, and sends the UL grant to theUE. Furthermore, the eNB sets up a soft buffer size corresponding to thesize of the data. In this case, the eNB may set up a soft buffer sizecorresponding to the maximum supportable size of data (i.e., L₁).

If the size of the data satisfies a predetermined condition (i.e., thesize of data<L₁) as described above, the UE may send the UL data using afast UL resource assignment procedure.

FIG. 24(b) illustrates an UL data transmission process in Case 2.

An embodiment of the present invention proposes a new scheduling requestmethod not including a BSR in order to send data of various sizes thatmay be intermittently generated as in “Case 2” more rapidly.

The present embodiment corresponds to a case where an event isintermittently generated as in “Case 1”, but data may be transmittedusing the aforementioned 3-step SR procedure not including a BSR throughtwo or more multiple SR configurations because data has various sizes.

In this case, an eNB previously defines a maximum supportable size ofdata L_(i) (i=1, 2, 3, . . . , M) corresponding to each SR type anddefines a corresponding soft buffer size.

Multiple SR configurations based on various sizes of data that may beused by pieces of UE may be controlled through an RRC message. That is,an M value may be controlled in order to control a number on which thesize of data is determined. Furthermore, the size of data supportablefor each SR type and information about an SR resource may also becontrolled through an RRC message.

Referring to FIG. 24(b), UE determines that the size of data transmittedin uplink corresponds to which range (L_(a)<the size of data<L_(b),wherein “a” and “b” belong to “i”) of sizes of data correspond torespective SR types supported in a multiple SR configuration at step2409.

The UE selects an SR type “j” according to the size of the data at step2411. That is, the UE selects a corresponding SR type depending onwhether the size of data belongs to which data range (L_(a)<the size ofdata<L_(b), wherein “a” and “b” belong to “i”).

Furthermore, the UE sends the selected SR type to an eNB through a PUCCHresource corresponding to the selected SR type at step 2413.

The eNB performs an UL grant generation and soft buffer configurationfor assigning the resources of UL data based on the size of dataobtained detecting the SR of the UE at step 2415.

More specifically, the eNB obtains information about the size of thedata (L_(a)<the size of data<L_(b), wherein “a” and “b” belong to “i”)based on the received SR type, generates an UL grant according to thesize of the data, and sends the UL grant to the UE. Furthermore, the eNBsets up a soft buffer size corresponding to the size of the data. Inthis case, the eNB may set up a soft buffer size corresponding to themaximum supportable size of data (i.e., L_(b)).

If the size of the data satisfies a predetermined condition (i.e.,L_(a)<the size of data<L_(b)) as described above, the UE may send the ULdata using a fast UL resource assignment procedure.

FIG. 25 is a diagram illustrating a method for requesting scheduling fortransmitting UL data in accordance with an embodiment of the presentinvention.

Referring to FIG. 25, UE receives multiple SR configuration informationfrom an eNB at step 2501.

The multiple SR configuration information includes information about aPUCCH resource index (i.e., an SR resource) corresponding to each SRtype. The SR resource configured for each SR type is determined by acombination of a PRB in which an SR is transmitted, a CS applied to abase sequence (e.g., a ZC sequence) for spreading the SR in a frequencydomain, and OC for spreading the SR in a time domain. Furthermore, theSR resource configured for each SR type may further include informationabout an SR periodicity and an SR subframe offset.

Furthermore, the multiple SR configuration information may includeinformation about the size of UL data corresponds to each SR type (e.g.,a maximum supportable size of data) or a maximum number of times that anSR is transmitted.

The UE may receive the multiple SR configuration information from theeNB through an RRC message. For example, the UE may receive the multipleSR configuration information from the eNB through an RRC connectionreconfiguration message or an RRC connection setup message.

Such multiple SR configuration information may be previously set betweenthe UE and the eNB and known to both the UE and the eNB. In this case,step 2501 may be omitted.

The UE selects an SR type that belongs to multiple SR types and thatcorresponds to the size of UL data to be transmitted to the eNB at step2503.

At least any one of the index of a physical uplink control channel(PUCCH) resource, an SR periodicity, or an SR subframe offset forsending an SR may be different set according to each of the multiple SRtypes.

Furthermore, the size of UL data is determined for each SR type. Forexample, a maximum supportable size of data may be differentlydetermined for each SR type. The UE checks the size of the UL data to betransmitted to the eNB and selects an SR type according to the range ofthe checked size of data.

The UE sends the selected SR type to the eNB in order to be assigned aPUSCH resource for sending the UL data at step 2505.

In this case, SRs corresponding to the respective SR types aretransmitted using an on/off keying method, but the index of PUCCHresources according to the SR types are differently set. That is, the UEsends an SR to the eNB through an SR resource (i.e., a PUCCH resourceindex) that has been set in the SR type corresponding to the UL data tobe transmitted.

The eNB attempts to detect all the SR types configured in the UE.

If the SR type transmitted by the UE indicates a procedure for assigninguplink resources through the transmission of an existing BSR of 6 bitsat step 2405 (i.e., if the SR corresponds to an SR type for sending aBSR), the UE receives an UL grant for sending a BSR from the eNB at step2507.

The UE that has received the UL grant for the BSR from the eNB sends atriggered BSR to the eNB through a PUSCH resource assigned by thereceived UL grant at step 2509.

In this case, if the SR type transmitted by the UE does not indicate aprocedure for assigning uplink resources through the transmission of anexisting BSR of 6 bits, step 2507 and step 2509 may be omitted.

The eNB obtains information about the size of the UL data through the SRtype received from the UE at step 2511.

The eNB identifies the SR type through a resource in which the SR istransmitted and obtains information about the size of the UL data to betransmitted by the UE in uplink using the SR type.

When the eNB receives a BSR from the UE after step 2507 and step 2509are performed, the eNB may obtain information about the size of UL datato be actually transmitted by the UE in uplink through the received BSR.

The UE receives an UL grant for the PUSCH resource for sending the ULdata from the eNB at step 2513.

That is, the eNB checks the size of the UL data to be actuallytransmitted by the UE in uplink through the received SR type (or BSR)and sends the UL grant for the PUSCH resource for sending the actualdata to the UE. Furthermore, the eNB sets up a soft buffer sizecorresponding to the size of the UL data to be transmitted by the UE inuplink based on the received SR type (or BSR).

The UE that has received the UL grant for sending the actual data fromthe eNB sends the actual UL data to the eNB through the PUSCH resourceassigned by the UL grant at step 2515.

As described above, in the scheduling method in accordance with anembodiment of the present invention, the existing 5-step UL resourceassignment procedure or the 3-step UL resource assignment procedure maybe performed according to an SR type transmitted by UE because aplurality of SR types is configured in the UE without changing theexisting PUCCH formats. Furthermore, the existing 5-step schedulingrequest procedure can be reduced to the 3-step scheduling requestprocedure.

Furthermore, the scheduling method in accordance with an embodiment ofthe present invention is advantageous in that a collision is notgenerated between PUCCH ACK/NACK resources. If a multiple SRconfiguration overlaps with an existing SR, an existing SR+A/Nmultiplexing scheme is used without any change.

Furthermore, in the scheduling method in accordance with an embodimentof the present invention, a scheduling request according to theconventional 5-step UL resource assignment procedure can be reduced to 3steps. In the proposed method, since a BSR is omitted through themultiple SR configuration, UE can directly set a soft buffer for theassignment of an UL grant and UL data with respect to data to betransmitted by the UE in uplink immediately after a scheduling request.

Apparatus for Implementing the Present Invention

FIG. 26 is a block diagram of a wireless communication apparatusaccording to an embodiment of the present invention.

Referring to FIG. 26, a wireless communication system includes an eNB2610 and a plurality of UEs 2620 belonging to the eNB 2610.

The eNB 2610 includes a processor 2611, a memory 2612, a radio frequency(RF) unit 2613. The processor 2611 may be configured to implement thefunctions, procedures and/or methods proposed by the present inventionas described in FIGS. 1-25. Layers of a wireless interface protocol maybe implemented by the processor 2611. The memory 2612 is connected tothe processor 2611 and stores various types of information for operatingthe processor 2611. The RF unit 2613 is connected to the processor 2611,transmits and/or receives an RF signal.

The UE 2620 includes a processor 2621, a memory 2622, and an RF unit2623. The processor 2621 may be configured to implement the functions,procedures and/or methods proposed by the present invention as describedin FIGS. 1-25. Layers of a wireless interface protocol may beimplemented by the processor 2621. The memory 2622 is connected to theprocessor 2611 and stores information related to operations of theprocessor 2622. The RF unit 2623 is connected to the processor 2611,transmits and/or receives an RF signal.

The memories 2612 and 2622 may be located inside or outside theprocessors 2611 and 2621 and may be connected to the processors 2611 and2621 through various well-known means. The eNB 2610 and/or UE 2620 mayinclude a single antenna or multiple antennas.

The aforementioned embodiments are achieved by combination of structuralelements and features of the present invention in a predeterminedmanner. Each of the structural elements or features should be consideredselectively unless specified separately. Each of the structural elementsor features may be carried out without being combined with otherstructural elements or features. Also, some structural elements and/orfeatures may be combined with one another to constitute the embodimentsof the present invention. The order of operations described in theembodiments of the present invention may be changed. Some structuralelements or features of one embodiment may be included in anotherembodiment, or may be replaced with corresponding structural elements orfeatures of another embodiment. Moreover, it will be apparent that someclaims referring to specific claims may be combined with another claimsreferring to the other claims other than the specific claims toconstitute the embodiment or add new claims by means of amendment afterthe application is filed.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the present inventionwithout departing from the spirit or scope of the inventions. Thus, itis intended that the present invention covers the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

INDUSTRIAL APPLICABILITY

Although the method for requesting scheduling for transmitting UL datain the wireless communication system of the present invention isdescribed mainly for the example applied to 3GPP LTE/LTE-A system, it isalso possible to be applied to various wireless communication system aswell as 3GPP LTE/LTE-A system.

What is claimed is:
 1. A method of requesting scheduling fortransmission of uplink (UL) data in a wireless communication system, themethod performed by a user equipment (UE) and comprising: transmitting aScheduling Request (SR) to an eNB through an SR resource selected from aplurality of SR resources corresponding to multiple SR types; receivingan UL grant according to an SR type corresponding to the selected SRresource from the eNB; and transmitting UL data to the eNB through aphysical uplink shared channel (PUSCH) resource allocated by the ULgrant.
 2. The method of claim 1, wherein at least an index of a physicaluplink control channel (PUCCH) resource, an SR periodicity, or an SRsubframe offset for sending the SR is configured differently accordingto each of the multiple SR types.
 3. The method of claim 1, wherein asize of the UL data is determined for each of the multiple SR types. 4.The method of claim 3, wherein the PUSCH resource allocated by the ULgrant is determined based on the size of the UL data according to theselected SR type.
 5. The method of claim 3, wherein a size of a softbuffer set by the eNB is determined based on the size of the UL dataaccording to the selected SR type.
 6. The method of claim 1, wherein aresource allocation procedure for transmitting the UL data is determinedaccording to the multiple SR types.
 7. The method of claim 1, furthercomprising receiving multiple SR configuration information from the eNBfor configuring the multiple SR types.
 8. The method of claim 7, whereinthe multiple SR configuration information includes at least informationrelated an index of a PUCCH resource, an SR periodicity, or an SRsubframe offset corresponding to each of the multiple SR types.
 9. Themethod of claim 1, further comprising: receiving an UL grant from theeNB for sending a Buffer Status Report (BSR) if the SR is an SR forsending the BSR; and transmitting the BSR to the eNB through a PUSCHresource allocated by the UL grant for transmitting the BSR.
 10. A userequipment (UE) requesting scheduling for transmission of uplink (UL)data in a wireless communication system, the UE comprising: a RadioFrequency (RF) unit configured to transmit and receive radio signals;and a processor configured to: control the RF unit to transmit aScheduling Request (SR) to an eNB through an SR resource selected from aplurality of SR resources corresponding to multiple SR types, controlthe RF unit to receive an UL grant according to an SR type correspondingto the selected SR resource from the eNB; and control the RF unit totransmit UL data to the eNB through a physical uplink shared channel(PUSCH) resource allocated by the UL grant.
 11. The UE of claim 10,wherein at least an index of a physical uplink control channel (PUCCH)resource, an SR periodicity, or an SR subframe offset for sending the SRis configured differently according to each of the multiple SR types.12. The UE of claim 10, wherein a size of the UL data is determined foreach of the multiple SR types.
 13. The UE of claim 12, wherein the PUSCHresource allocated by the UL grant is determined based on the size ofthe UL data according to the selected SR type.
 14. The UE of claim 12,wherein a size of a soft buffer set by the eNB is determined based onthe size of the UL data according to the selected SR type.
 15. The UE ofclaim 10, wherein a resource allocation procedure for sending the ULdata is determined according to the multiple SR types.
 16. The UE ofclaim 10, wherein the processor is further configured to control the RFunit to receive multiple SR configuration information from the eNB forconfiguring the multiple SR types.
 17. The UE of claim 16, wherein themultiple SR configuration information includes at least informationrelated an index of a PUCCH resource, an SR periodicity, or an SRsubframe offset corresponding to each of the multiple SR types.
 18. TheUE of claim 10, wherein the processor is further configured to: controlthe RF unit to receive an UL grant from the eNB for sending a BufferStatus Report (BSR) if the SR is an SR for sending the BSR; and controlthe RF unit to transmit the BSR to the eNB through a PUSCH resourceallocated by the UL grant for transmitting the BSR.